Relative and Absolute Contraindications to Thrombolysis

Thrombolysis is a treatment option for patients with ongoing cardiac ischemia and presentation within 12 hours of onset of pain. However, there are both relative and absolute contraindications to this treatment.

Absolute contraindications include internal or heavy PV bleeding, acute pancreatitis or severe liver disease, esophageal varices, active lung disease with cavitation, recent trauma or surgery within the past 2 weeks, severe hypertension (>200/120 mmHg), suspected aortic dissection, recent hemorrhagic stroke, cerebral neoplasm, and previous allergic reaction.

Relative contraindications include prolonged CPR, history of CVA, bleeding diathesis, anticoagulation, blood pressure of 180/100 mmHg, peptic ulcer, and pregnancy or recent delivery.

It is important to consider these contraindications before administering thrombolysis as they can increase the risk of complications. Primary percutaneous coronary intervention is the preferred treatment option, but if not available, thrombolysis can be a viable alternative. The benefit of thrombolysis decreases over time, and a target time of <30 minutes from admission for commencement of thrombolysis is typically recommended.

Common Heart Murmurs and their Characteristics

Heart murmurs are abnormal sounds heard during the cardiac cycle. They can be caused by a variety of conditions, including valve disorders. Here are some common heart murmurs and their characteristics:

Tricuspid Regurgitation: This condition leads to an elevated jugular venous pressure (JVP) with large V-waves and a pan-systolic murmur at the left sternal edge. Other features include pulsatile hepatomegaly and left parasternal heave.

Tricuspid Stenosis: Tricuspid stenosis causes a mid-diastolic murmur heard best at the left sternal border.

Pulmonary Stenosis: Pulmonary stenosis causes an ejection systolic murmur in the second left intercostal space.

Mitral Regurgitation: Mitral regurgitation causes a pan-systolic murmur at the apex, which radiates to the axilla.

Mitral Stenosis: Mitral stenosis causes a mid-diastolic murmur at the apex, and severe cases may have secondary pulmonary hypertension (a cause of tricuspid regurgitation).

Knowing the characteristics of these murmurs can aid in their diagnosis and management. It is important to consult with a healthcare professional if you suspect you may have a heart murmur.

During embryonic development, the septum primum grows down from the roof of the primitive atrium and fuses with the endocardial cushions. It initially has a hole called the ostium primum, which closes as the septum grows downwards. However, a second hole called the ostium secundum develops in the septum primum before fusion can occur. The septum secundum then grows downwards and to the right of the septum primum and ostium secundum. The foramen ovale is a passage through the septum secundum that allows blood to shunt from the right to the left atrium in the fetus, bypassing the pulmonary circulation. This defect closes at birth due to a drop in pressure within the pulmonary circulation after the infant takes a breath. If there is overlap between the foramen ovale and ostium secundum or if the ostium primum fails to close, an atrial septal defect results. This defect does not cause cyanosis because oxygenated blood flows from left to right through the defect.

Treatment Options for Pulmonary Hypertension

Pulmonary hypertension (PAH) is a condition that can cause shortness of breath, weakness, and tiredness. A high-pitched decrescendo murmur may indicate pulmonary regurgitation and PAH. Diuretics can help reduce the pressure on the right ventricle and remove excess fluid. Oxygen therapy can improve exercise tolerance, and bosentan can slow the progression of PAH by inhibiting vasoconstriction. Salbutamol and ipratropium inhalers are appropriate for COPD, but not for PAH. Salbutamol nebulizer and supplemental oxygen are appropriate for acute exacerbations of asthma or COPD, but not for PAH. Aortic valve replacement is not indicated for PAH. Antiplatelets may be helpful for reducing the risk of thrombosis. Increasing bisoprolol may be helpful for atrial flutter, but not for PAH. High-dose calcium-channel blockers may be used for PAH with right heart failure under senior supervision/consultation.

Clarithromycin and its Drug Interactions

Clarithromycin is an antibiotic used to treat various bacterial infections. It is effective against many Gram positive and some Gram negative bacteria that cause community acquired pneumonias, atypical pneumonias, upper respiratory tract infections, and skin infections. Unlike other macrolide antibiotics, clarithromycin is highly stable in acidic environments and has fewer gastric side effects. It is also safe to use in patients with penicillin allergies.

However, clarithromycin can interact with other drugs by inhibiting the hepatic cytochrome P450 enzyme system. This can lead to increased levels of other drugs that are metabolized via this route, such as warfarin, aminophylline, and statin drugs. When taken with statins, clarithromycin can cause muscle breakdown and rhabdomyolysis, which can lead to renal failure. Elderly patients who take both drugs may experience reduced mobility and require prolonged rehabilitation physiotherapy.

To avoid these interactions, it is recommended that patients taking simvastatin or another statin drug discontinue its use during the course of clarithromycin treatment and for one week after. Clarithromycin can also potentially interact with clopidogrel, a drug used to prevent stent thrombosis, by reducing its efficacy. However, clarithromycin does not have any recognized interactions with bisoprolol, lisinopril, or aspirin.

In summary, while clarithromycin is an effective antibiotic, it is important to be aware of its potential drug interactions, particularly with statin drugs and clopidogrel. Patients should always inform their healthcare provider of all medications they are taking to avoid any adverse effects.

Complications of Myocardial Infarction

Myocardial infarction (MI) is a serious medical condition that can lead to various complications. Among these complications, ventricular arrhythmia is the most common cause of death. Malignant ventricular arrhythmias require immediate direct current (DC) electrical therapy to terminate the arrhythmias. Mural thrombosis, although it may cause systemic emboli, is not a common cause of death. Myocardial wall rupture and muscular rupture typically occur 4-7 days post-infarction, while papillary muscle rupture is also a possibility. Pulmonary edema, which can be life-threatening, is accompanied by symptoms of breathlessness and orthopnea. However, it can be treated effectively with oxygen, positive pressure therapy, and vasodilators.

Understanding the Complications of Myocardial Infarction

Auscultation of Heart Valves: Locations and Sounds

The human heart has four valves that regulate blood flow. These valves can be heard through auscultation, a medical technique that involves listening to the sounds produced by the heart using a stethoscope. Here are the locations and sounds of each valve:

Tricuspid Valve: This valve is located on the right side of the heart and can be heard at the left sternal border in the fourth intercostal space. The sound produced by this valve is a low-pitched, rumbling noise.

Aortic Valve: The aortic valve is located on the left side of the heart and can be heard over the right sternal border at the second intercostal space. The sound produced by this valve is a high-pitched, clicking noise.

Pulmonary Valve: This valve is located on the right side of the heart and can be heard over the left sternal border at the second intercostal space. The sound produced by this valve is a high-pitched, clicking noise.

Thebesian Valve: The Thebesian valve is located in the coronary sinus and its closure cannot be auscultated.

Mitral Valve: This valve is located on the left side of the heart and can be heard by listening at the apex, in the left mid-clavicular line in the fifth intercostal space. The sound produced by this valve is a low-pitched, rumbling noise.

In summary, auscultation of heart valves is an important diagnostic tool that can help healthcare professionals identify potential heart problems. By knowing the locations and sounds of each valve, healthcare professionals can accurately diagnose and treat heart conditions.

Types of Cardiomyopathy and Congenital Heart Defects

Cardiomyopathy is a group of heart diseases that affect the structure and function of the heart muscle. There are different types of cardiomyopathy, each with its own causes and symptoms. Additionally, there are congenital heart defects that can affect the heart’s structure and function from birth. Here are some of the most common types:

1. Hypertrophic cardiomyopathy: This is an inherited condition that causes the heart muscle to thicken, making it harder for the heart to pump blood. It can lead to sudden death in young athletes.

2. Restrictive cardiomyopathy: This is a rare form of cardiomyopathy that is caused by diseases that restrict the heart’s ability to fill with blood during diastole.

3. Dilated cardiomyopathy: This is the most common type of cardiomyopathy, which causes the heart chambers to enlarge and weaken, leading to heart failure.

4. Mitral stenosis: This is a narrowing of the mitral valve, which can impede blood flow between the left atrium and ventricle.

In addition to these types of cardiomyopathy, there are also congenital heart defects, such as ventricular septal defect, which is the most common congenital heart defect. This condition creates a direct connection between the right and left ventricles, affecting the heart’s ability to pump blood effectively.

Understanding the different types of cardiomyopathy and congenital heart defects is important for proper diagnosis and treatment. If you experience symptoms such as chest pain, shortness of breath, or fatigue, it is important to seek medical attention promptly.

This patient has high cholesterol and hypertension, both of which require immediate attention.

Medications:
The patient will start taking atorvastatin 20 mg once a night to address their high cholesterol. After three months, their cholesterol and full lipid profile will be rechecked, and the therapy will be titrated to maintain a total cholesterol of <5. If necessary, the dose may be increased to 40 mg once a night.

For hypertension, the patient will start taking a calcium channel blocker as they are over the age of 55. The blood pressure will be monitored regularly, and if it rises above 150/90, additional treatment may be necessary.

Monitoring:
The patient’s cholesterol and full lipid profile will be rechecked after three months of treatment with atorvastatin. The aim is to see a 40% reduction in non-HDL cholesterol. If this is not achieved, a discussion of adherence, lifestyle measures, and the possibility of increasing the dose will take place.

The patient’s blood pressure will also be monitored regularly. If it rises above 150/90, additional treatment may be necessary.

Differentiating Cardiac Conditions: Causes and Risks

Cardiac conditions can have varying causes and risks, making it important to differentiate between them. Essential hypertension, for example, is characterized by uniform left ventricular hypertrophy and is a major risk factor for stroke. On the other hand, atrial fibrillation is a common cause of stroke but does not cause left ventricular hypertrophy and is rarer with normal atrial size. Hypertrophic obstructive cardiomyopathy, which is more common in men and often has a familial tendency, typically causes asymmetric hypertrophy of the septum and apex and can lead to arrhythmogenic or unexplained sudden cardiac death. Dilated cardiomyopathies, such as idiopathic dilated cardiomyopathy, often have no clear precipitant but cause a dilated left ventricular size, increasing the risk for a mural thrombus and an embolic risk. Finally, tuberculous pericarditis is difficult to diagnose due to non-specific features such as cough, dyspnoea, sweats, and weight loss, with typical constrictive pericarditis findings being very late features with fluid overload and severe dyspnoea. Understanding the causes and risks associated with these cardiac conditions can aid in their proper diagnosis and management.

Acute Rheumatic Fever

Acute rheumatic fever is a condition that occurs after a bacterial infection and is caused by pathogenic antibodies. It is characterized by a systemic inflammatory response that affects the heart, joints, and skin. The condition is triggered by antibodies that cross-react with cardiac tissue, which can lead to pancarditis, arthritis, and intra-dermal inflammation. The diagnosis of acute rheumatic fever is based on a combination of clinical and investigatory findings, which are known as the revised Jones criteria.

The pancarditis associated with acute rheumatic fever can cause a sustained tachycardia, which is particularly prominent at night. Conduction abnormalities, including prolonged PR interval, are also common. Pericarditis may be detected clinically with a pericardial rub, and patients may exhibit features of congestive cardiac failure, such as cardiomegaly. Several murmurs are recognized in patients with acute rheumatic fever, including aortic regurgitation, mitral regurgitation, and the Carey Coombs murmur.

In summary, acute rheumatic fever is a serious condition that can have significant effects on the heart, joints, and skin. Early diagnosis and treatment are essential to prevent complications and improve outcomes. The revised Jones criteria provide guidance for clinicians in making an accurate diagnosis and initiating appropriate treatment.

Anatomy of the Heart: Intercostal Spaces and Auscultation Positions

The human heart is a vital organ responsible for pumping blood throughout the body. Understanding its anatomy is crucial for medical professionals to diagnose and treat various heart conditions. In this article, we will discuss the intercostal spaces and auscultation positions related to the heart.

Left Fifth Intercostal Space: Apex of the Heart
The apex of the heart is located deep to the left fifth intercostal space, approximately 8-9 cm from the mid-sternal line. This is an important landmark for cardiac examination and procedures.

Left Fourth Intercostal Space: Left Ventricle
The left ventricle, one of the four chambers of the heart, is located superior to the apex and can be auscultated in the left fourth intercostal space.

Right Fourth Intercostal Space: Right Atrium
The right atrium, another chamber of the heart, is located immediately lateral to the right sternal margin at the right fourth intercostal space.

Left Second Intercostal Space: Pulmonary Valve
The pulmonary valve, which regulates blood flow from the right ventricle to the lungs, can be auscultated in the left second intercostal space, immediately lateral to the left sternal margin.

Right Fifth Intercostal Space: Incorrect Location
The right fifth intercostal space is an incorrect location for cardiac examination because the apex of the heart is located on the left side.

In conclusion, understanding the intercostal spaces and auscultation positions related to the heart is essential for medical professionals to accurately diagnose and treat various heart conditions.

Differentiating Heart Murmurs: Causes and Characteristics

Heart murmurs are abnormal sounds heard during a heartbeat and can indicate underlying heart conditions. Here are some common causes and characteristics of heart murmurs:

Mitral Stenosis: This condition is most commonly caused by rheumatic fever in childhood and is rare in developed countries. Patients with mitral stenosis will have a loud S1 with an associated opening snap. However, if the mitral valve is calcified or there is severe stenosis, the opening snap may be absent and S1 soft.

Mitral Regurgitation and Ventricular Septal Defect: These conditions cause a pan-systolic murmur, which is not the correct option for differentiating heart murmurs.

Aortic Regurgitation: This condition leads to an early diastolic murmur.

Aortic Stenosis: Aortic stenosis causes an ejection systolic murmur.

Ventricular Septal Defect: As discussed, a ventricular septal defect will cause a pan-systolic murmur.

By understanding the causes and characteristics of different heart murmurs, healthcare professionals can better diagnose and treat underlying heart conditions.

Somatisation Disorder as the Most Likely Diagnosis

Somatisation disorder is the most probable diagnosis for the given scenario, although it lacks sufficient criteria for a complete diagnosis. This disorder is characterised by recurring pains, gastrointestinal, sexual, and pseudo-neurologic symptoms that persist for years. To meet the diagnostic criteria, the patient’s physical complaints must not be intentionally induced and must result in medical attention or significant impairment in social, occupational, or other important areas of functioning. Typically, the first symptoms appear during adolescence, and the full criteria are met by the age of 30.

Among the other disorders, factitious disorder is the least likely explanation. The other three disorders are possible explanations, but they are not as likely as somatisation disorder.

Investigating Hypertension in a Young Patient: The Importance of Aldosterone-to-Renin Ratio

Hypertension in a young patient with hypernatraemia and hypokalaemia can be caused by renal artery stenosis or an aldosterone-secreting adrenal adenoma. To determine the cause, measuring aldosterone levels alone is not enough. Both renin and aldosterone levels should be measured, and the aldosterone-to-renin ratio should be evaluated. If hyperaldosteronism is confirmed, CT or MRI of the adrenal glands is done to locate the cause. If both are normal, adrenal vein sampling may be performed. MR angiogram of renal arteries is not a first-line investigation. Similarly, CT angiogram of renal arteries should not be the first choice. 24-hour urine metanephrine levels are not useful in this scenario. The electrolyte abnormalities point towards elevated aldosterone levels, not towards a phaeochromocytoma.

Complications of Transmural Myocardial Infarction

Transmural myocardial infarction can lead to various complications, including Dressler’s syndrome and ventricular aneurysm. Dressler’s syndrome typically occurs weeks to months after an infarction and is characterized by acute fibrinous pericarditis, fever, pleuritic chest pain, and leukocytosis. On the other hand, ventricular aneurysm is characterized by a systolic bulge in the precordial area and predisposes to stasis and thrombus formation. Acute fibrinous pericarditis, which manifests a few days after an infarction, is not due to an autoimmune reaction. Reinfarction is unlikely in a patient who has undergone successful treatment for STEMI. Infectious myocarditis, caused by viruses such as Coxsackie B, Epstein-Barr, adenovirus, and echovirus, is not the most likely cause of the patient’s symptoms, given his medical history.

Complications of Transmural Myocardial Infarction

The patient is experiencing cardiac tamponade, which is caused by fluid in the pericardial sac compressing the heart and reducing ventricular filling. This is likely due to pericarditis caused by recent radiotherapy. Beck’s triad of low blood pressure, raised JVP, and muffled heart sounds are indicative of tamponade. Urgent pericardiocentesis is necessary to aspirate the pericardial fluid, and echocardiographic guidance is the safest method. Ibuprofen is the initial treatment for acute pericarditis without haemodynamic compromise, but in severe cases like this, it will not help. A fluid challenge with 1 litre of sodium chloride is not recommended as it may worsen the pericardial fluid. GTN spray, morphine, clopidogrel, and aspirin are useful in managing an MI, but not tamponade. LMWH is important in managing a PE, but not tamponade, and may even worsen the condition if caused by haemopericardium.

Alcohol and its Effects on Cardiomyopathy: Understanding the Relationship

Alcohol consumption has been linked to various forms of cardiomyopathy, a condition that affects the heart muscle. One of the most common types of cardiomyopathy is dilated cardiomyopathy, which is characterized by the dilation of all four chambers of the heart. This condition results in increased end-diastolic volume, decreased contractility, and depressed ejection fraction. Chronic alcohol use is a significant cause of dilated cardiomyopathy, along with viral infections, toxins, genetic mutations, and trypanosome infections.

Chagas’ disease, caused by trypanosomes, can lead to cardiomyopathy, resulting in the dilation of all four chambers of the heart. On the other hand, alcoholic cardiomyopathy leads to the dilation of all four chambers of the heart, including the atria. Alcohol consumption can also cause concentric hypertrophy of the left ventricle, which is commonly seen in long-term hypertension. Asymmetric hypertrophy of the interventricular septum is another form of cardiomyopathy that can result from alcohol consumption. This condition is known as hypertrophic cardiomyopathy, a genetic disease that can lead to sudden cardiac death in young athletes.

In conclusion, understanding the relationship between alcohol consumption and cardiomyopathy is crucial in preventing and managing this condition. It is essential to limit alcohol intake and seek medical attention if any symptoms of cardiomyopathy are present.

Management of Stable Angina: Adding Isosorbide Mononitrate and Arranging Outpatient Angiogram

For a patient with stable angina who is already taking appropriate first-line medications such as bisoprolol and GTN, the next step in management would be to add a long-acting nitrate like isosorbide mononitrate. This medication provides longer-term vasodilation compared to GTN, which is only used when required. This can potentially reduce the frequency of angina symptoms.

An outpatient angiogram should also be arranged for the patient. While stable angina does not require an urgent angiogram, performing one on a non-urgent basis can provide more definitive management options like stenting if necessary.

Increasing the dose of ramipril or statin is not necessary unless there is evidence of worsening hypertension or high cholesterol levels, respectively. Overall, the management of stable angina should be tailored to the individual patient’s needs and risk factors.

Tips for a Hypertension-Friendly Diet

Maintaining a healthy diet is crucial for managing hypertension. Here are some tips to help you make the right food choices:

1. Load up on fruits and vegetables: Consuming a diet rich in fruits and vegetables can reduce blood pressure by 2-8 mmHg in hypertensive patients. It can also aid in weight loss, which further lowers the risk of hypertension.

2. Limit cholesterol intake: A reduction in cholesterol is essential for patients with ischaemic heart disease, and eating foods that are low in fat and cholesterol can reduce blood pressure.

3. Moderate alcohol consumption: Men should have no more than two alcoholic drinks daily to lower their risk of hypertension.

4. Eat oily fish twice a week: Eating more fish can help lower blood pressure, but having oily fish twice weekly is advised for patients with ischaemic heart disease, not hypertension alone.

5. Watch your sodium intake: Restricting dietary sodium is recommended and can lower blood pressure. A low sodium diet contains less than 2 g of sodium daily. Aim for a maximum of 7 g of dietary sodium daily.

By following these tips, you can maintain a hypertension-friendly diet and reduce your risk of complications.

Treatment Options for Cardiogenic Shock Following Acute Myocardial Infarction

Cardiogenic shock following an acute myocardial infarction is a serious condition that requires prompt and appropriate treatment. One potential treatment option is the use of an intra-aortic balloon pump, which can provide ventricular support without compromising blood pressure. High-dose dopamine may also be used to preserve renal function, but intermediate and high doses can have negative effects on renal blood flow. The chance of death in this situation is high, but with appropriate treatment, it can be reduced to less than 10%. Nesiritide, a synthetic natriuretic peptide, is not recommended as it can worsen renal function and increase mortality. Nitrate therapy should also be avoided as it can further reduce renal perfusion and worsen the patient’s condition. Overall, careful consideration of treatment options is necessary to improve outcomes for patients with cardiogenic shock following an acute myocardial infarction.

Treatment Options for Atrial Fibrillation in a Patient with Heart Failure

When treating a patient with atrial fibrillation (AF) and heart failure, the aim should be rate control. While bisoprolol is a good choice, it may not be suitable for a patient with chronic low blood pressure. In this case, digoxin would be the treatment of choice. Anticoagulation with a NOAC or warfarin is also necessary. Cardioversion with amiodarone should not be the first line of treatment due to the patient’s heart failure. Increasing the dose of bisoprolol may not be the best option either. Amlodipine is not effective for rate control in AF, and calcium-channel blockers should not be used in heart failure. Electrical cardioversion is not appropriate for this patient. Overall, the treatment plan should be tailored to the patient’s individual needs and medical history.

Managing Atrial Fibrillation and Heart Failure: Treatment Options

Management of Suspected Myocardial Infarction

Explanation:

When a patient presents with symptoms suggestive of myocardial infarction (MI), a troponin level should be checked. If the level is only slightly raised, it does not confirm a diagnosis of MI, but neither does it rule it out. Therefore, a repeat troponin level should be performed at least 3 hours after the first level and sent as urgent.

In an MI, cardiac enzymes are released from dead myocytes into the blood, causing enzyme levels to rise and eventually fall as they are cleared from blood. If the patient has had an MI, the repeat troponin level should either be further raised or further reduced. If the level remains roughly constant, then an alternative cause should be sought, such as pulmonary embolism, chronic kidney disease, acute kidney injury, pericarditis, heart failure, or sepsis/systemic infection.

Admission to the Coronary Care Unit (CCU) is not warranted yet. Further investigations should be performed to ascertain whether an admission is needed or whether alternative diagnoses should be explored.

Safety-netting and return to the GP should include a repeat troponin level to see if the level is stable (arguing against an MI) or is rising/falling. A repeat electrocardiogram (ECG) should be performed, and a thorough history and examination should be obtained to identify any urgent diagnoses that need to be explored before the patient is discharged.

Thrombolysis carries a risk for bleeding, so it requires a clear indication, which has not yet been obtained. Therefore, it should not be administered without proper evaluation.

The alanine transaminase (ALT) level has been used as a marker of MI in the past, but it has been since superseded as it is not specific for myocardial damage. In fact, it is now used as a component of liver function tests.

Valvular Murmurs

Valvular murmurs are a common topic in medical exams, and it is crucial to have a good of them. The easiest way to approach them is by classifying them into systolic and diastolic murmurs. If the arterial valves, such as the aortic or pulmonary valves, are narrowed, ventricular contraction will cause turbulent flow, resulting in a systolic murmur. On the other hand, if these valves are incompetent, blood will leak back through the valve during diastole, causing a diastolic murmur.

Similarly, the atrioventricular valves, such as the mitral and tricuspid valves, can be thought of in the same way. If these valves are leaky, blood will be forced back into the atria during systole, causing a systolic murmur. If they are narrowed, blood will not flow freely from the atria to the ventricles during diastole, causing a diastolic murmur.

Therefore, a diastolic murmur indicates either aortic/pulmonary regurgitation or mitral/tricuspid stenosis. The loud first heart sound is due to increased force in closing the mitral or tricuspid valve, which suggests stenosis. the different types of valvular murmurs and their causes is essential for medical professionals to diagnose and treat patients accurately.

SVT is a type of arrhythmia that occurs above the ventricles and is commonly seen in patients in their 20s with alcohol and drug use as precipitating factors. Early evaluation of ABC is important, and vagal manoeuvres are recommended as the first line of treatment. Adenosine is the drug of choice if vagal manoeuvres fail, and DC cardioversion is required if signs of decompensation are present. Amiodarone is not a first-line treatment for regular narrow complex SVT.

Pericarditis as a Post-Viral Complication: Symptoms and Differential Diagnosis

Pericarditis, inflammation of the pericardium, can occur as a post-viral complication. Patients typically experience diffuse chest pain that improves when leaning forward, and a friction rub may be heard on cardiac auscultation. Diffuse ST segment elevations on ECG can be mistaken for myocardial infarction. In this case, the patient reported recent viral symptoms and then developed acute pericardial symptoms.

While systemic lupus erythematosus (SLE) can cause pericarditis, other symptoms such as rash, myalgia, or joint pain would be expected, along with a positive anti-nuclear antibodies test. Uraemia can also cause pericarditis, but elevated blood urea nitrogen would be present, and this patient has no history of kidney disease. Dressler syndrome, or post-myocardial infarction pericarditis, can cause diffuse ST elevations, but does not represent transmural infarction. Chest radiation can also cause pericarditis, but this patient has no history of radiation exposure.

The Electrical Activity of the Heart and the ECG

The ECG (electrocardiogram) is a medical test that records the electrical activity of the heart. This activity is responsible for different parts of the ECG. The first part is the atrial depolarisation, which is represented by the P wave. This wave conducts down the bundle of His to the ventricles, causing the ventricular depolarisation. This is shown on the ECG as the QRS complex. Finally, the ventricular repolarisation is represented by the T wave.

It is important to note that atrial repolarisation is not visible on the ECG. This is because it is of lower amplitude compared to the QRS complex. the different parts of the ECG and their corresponding electrical activity can help medical professionals diagnose and treat various heart conditions.

Acute Aortic Dissection: Symptoms, Diagnosis, and Imaging

Acute aortic dissection is a medical emergency that causes sudden and severe chest pain. The pain is often described as tearing and may be felt in the front or back of the chest, as well as in the neck. Other symptoms and signs depend on the arteries involved and nearby organs affected. In severe cases, it can lead to hypovolemic shock and sudden death.

A chest x-ray can show a widened mediastinum, cardiomegaly, pleural effusion, and intimal calcification separated more than 6 mm from the edge. However, aortography is the gold standard for diagnosis, which shows the origin of arteries from true or false lumen. CT scan and MRI are also commonly used for diagnosis. Transoesophageal echo (TEE) is best for the descending aorta, while transthoracic echo (TTE) is best for the ascending aorta and arch.

In summary, acute aortic dissection is a serious condition that requires prompt diagnosis and treatment. Symptoms include sudden and severe chest pain, which may be accompanied by other signs depending on the arteries involved. Imaging techniques such as chest x-ray, aortography, CT scan, MRI, TEE, and TTE can aid in diagnosis.

Common Heart Conditions and Their Characteristics

Aortic stenosis is a condition where the aortic valve does not open completely, resulting in dyspnea, chest pain, and syncope. It produces a narrow pulse pressure, a low volume pulse, and an ejection systolic murmur that radiates to the carotids. An enlarged right ascending aorta is a common finding in aortic stenosis. Calcification of the valve is diagnostic and can be observed using CT or fluoroscopy. Aortic stenosis is commonly caused by calcification of the aortic valve due to a congenitally bicuspid valve, connective tissue disease, or rheumatic heart disease. Echocardiography confirms the diagnosis, and valve replacement or intervention is indicated with critical stenosis <0.5 cm or when symptomatic. Aortic regurgitation is characterized by a widened pulse pressure, collapsing pulse, and an early diastolic murmur heard loudest in the left lower sternal edge with the patient upright. Patients can be asymptomatic until heart failure manifests. Causes include calcification and previous rheumatic fever. Ventricular septal defect (VSD) is a congenital or acquired condition characterized by a pansystolic murmur heard loudest at the left sternal edge. Acquired VSD is mainly a result of previous myocardial infarction. VSD can be asymptomatic or cause heart failure secondary to pulmonary hypertension. Mitral regurgitation is characterized by a pansystolic murmur heard best at the apex that radiates towards the axilla. A third heart sound may also be heard. Patients can remain asymptomatic until dilated cardiac failure occurs, upon which dyspnea and peripheral edema are among the most common symptoms. Mitral stenosis causes a mid-diastolic rumble heard best at the apex with the patient in the left lateral decubitus position. Auscultation of the precordium may also reveal an opening snap. Patients are at increased risk of atrial fibrillation due to left atrial enlargement. The most common cause of mitral stenosis is a previous history of rheumatic fever.

Interpreting Chest X-Ray Findings in Heart Failure

Chest X-rays are commonly used to assess patients with heart failure. Here are some key findings to look out for:

– Patchy perihilar shadowing: This suggests alveolar oedema, which can arise due to fluid overload in heart failure. Intravenous fluids should be given slowly, with frequent re-assessment for signs of peripheral and pulmonary oedema.
– Cardiothoracic ratio of 0.5: A ratio of >0.5 on a postero-anterior (PA) chest X-ray may indicate heart failure. A ratio of 0.5 or less is considered normal.
– Patchy shadowing in lower zones: This may suggest consolidation caused by pneumonia, which can complicate heart failure.
– Prominent lower zone vessels: In pulmonary venous hypertension, there is redistribution of blood flow to the non-dependent upper lung zones, leading to larger vessels in the lower zones.
– Narrowing of the carina: This may suggest enlargement of the left atrium, which sits directly under the carina in the chest.