For patients with recurrent venous thromboembolic disease, an inferior vena cava filter may be considered. This is particularly relevant for patients with cancer who have experienced multiple DVTs despite being fully anticoagulated. Before considering an inferior vena cava filter, alternative treatments such as increasing the target INR to 3-4 for long-term high-intensity oral anticoagulant therapy or switching to LMWH should be considered. This recommendation is in line with NICE guidelines on the diagnosis, management, and thrombophilia testing of venous thromboembolic diseases. Prescribing apixaban, increasing the dose of dabigatran off-license, or prescribing Thrombo-Embolic Deterrent (TED) stockings are not appropriate solutions for this patient. Similarly, initiating end-of-life drugs and preparing the family is not indicated based on the clinical description provided.

Management of Pulmonary Embolism

Pulmonary embolism (PE) is a serious condition that requires prompt management. The National Institute for Health and Care Excellence (NICE) updated their guidelines on the management of venous thromboembolism (VTE) in 2020, with some key changes. One of the significant changes is the recommendation to use direct oral anticoagulants (DOACs) as the first-line treatment for most people with VTE, including those with active cancer. Another change is the increasing use of outpatient treatment for low-risk PE patients, determined by a validated risk stratification tool.

Anticoagulant therapy is the cornerstone of VTE management. The guidelines recommend using apixaban or rivaroxaban as the first-line treatment for PE, followed by LMWH, dabigatran, edoxaban, or a vitamin K antagonist (VKA) if necessary. For patients with active cancer, DOACs are now recommended instead of LMWH. The length of anticoagulation depends on whether the VTE was provoked or unprovoked, with treatment typically lasting for at least three months. Patients with unprovoked VTE may continue treatment for up to six months, depending on their risk of recurrence and bleeding.

In cases of haemodynamic instability, thrombolysis is recommended as the first-line treatment for massive PE with circulatory failure. Other invasive approaches may also be considered where appropriate facilities exist. Patients who have repeat pulmonary embolisms, despite adequate anticoagulation, may be considered for inferior vena cava (IVC) filters. However, the evidence base for IVC filter use is weak, and further studies are needed.

Carcinoid Syndrome and its Diagnosis

Carcinoid syndrome is characterized by the presence of vasoactive amines such as serotonin in the bloodstream, leading to various clinical features. The primary carcinoid tumor is usually found in the small intestine or appendix, but it may not cause significant symptoms as the liver detoxifies the blood of these amines. However, systemic effects occur when malignant cells spread to other organs, such as the lungs, which are not part of the portal circulation. One of the complications of carcinoid syndrome is damage to the right heart valves, which can cause tricuspid regurgitation, as evidenced by a pulsatile liver and pansystolic murmur.

To diagnose carcinoid syndrome, the 5-HIAA test is usually performed, which measures the breakdown product of serotonin in a 24-hour urine collection. If the test is positive, imaging and histology are necessary to confirm malignancy.

Clopidogrel works by blocking ADP receptors, which prevents platelet activation and the formation of blood clots.

Aspirin and other NSAIDs inhibit the COX-1 enzyme, leading to a decrease in prostaglandins and thromboxane, which helps to prevent blood clots.

Antiplatelet medications like abciximab and eptifibatide work by blocking glycoprotein IIb/IIIa receptors on platelets, which prevents platelet adhesion and activation.

Increasing thrombomodulin expression and prostacyclin levels would have the opposite effect and increase blood coagulability and platelet production.

Clopidogrel: An Antiplatelet Agent for Cardiovascular Disease

Clopidogrel is a medication used to manage cardiovascular disease by preventing platelets from sticking together and forming clots. It is commonly used in patients with acute coronary syndrome and is now also recommended as a first-line treatment for patients following an ischaemic stroke or with peripheral arterial disease. Clopidogrel belongs to a class of drugs called thienopyridines, which work in a similar way. Other examples of thienopyridines include prasugrel, ticagrelor, and ticlopidine.

Clopidogrel works by blocking the P2Y12 adenosine diphosphate (ADP) receptor, which prevents platelets from becoming activated. However, concurrent use of proton pump inhibitors (PPIs) may make clopidogrel less effective. The Medicines and Healthcare products Regulatory Agency (MHRA) issued a warning in July 2009 about this interaction, and although evidence is inconsistent, omeprazole and esomeprazole are still cause for concern. Other PPIs, such as lansoprazole, are generally considered safe to use with clopidogrel. It is important to consult with a healthcare provider before taking any new medications or supplements.

The hyperpigmentation observed in patients with varicose eczema/venous ulcers is likely caused by haemosiderin deposition. This occurs when red blood cells burst due to venous stasis, leading to the release of haemoglobin which is stored as haemosiderin. The excess haemosiderin causes a local red-brown discolouration around areas of varicose veins.

Acanthosis nigricans is an unlikely cause as it is associated with metabolic disorders and not varicose veins. Atrophie blanche describes hypopigmentation seen in venous ulcers, while lipodermatosclerosis causes thickening of the skin in varicose veins without changing the skin color. Melanoma, a skin cancer that causes dark discolouration, is unlikely to be associated with varicose veins and is an unlikely explanation for the observed discolouration on the back of the calf.

Understanding Varicose Veins

Varicose veins are enlarged and twisted veins that occur when the valves in the veins become weak or damaged, causing blood to flow backward and pool in the veins. They are most commonly found in the legs and can be caused by various factors such as age, gender, pregnancy, obesity, and genetics. While many people seek treatment for cosmetic reasons, others may experience symptoms such as aching, throbbing, and itching. In severe cases, varicose veins can lead to skin changes, bleeding, superficial thrombophlebitis, and venous ulceration.

To diagnose varicose veins, a venous duplex ultrasound is typically performed to detect retrograde venous flow. Treatment options vary depending on the severity of the condition. Conservative treatments such as leg elevation, weight loss, regular exercise, and compression stockings may be recommended for mild cases. However, patients with significant or troublesome symptoms, skin changes, or a history of bleeding or ulcers may require referral to a specialist for further evaluation and treatment. Possible treatments include endothermal ablation, foam sclerotherapy, or surgery.

In summary, varicose veins are a common condition that can cause discomfort and cosmetic concerns. While many cases do not require intervention, it is important to seek medical attention if symptoms or complications arise. With proper diagnosis and treatment, patients can manage their condition and improve their quality of life.

The atrioventricular node is most likely supplied by the right coronary artery.

The left coronary artery gives rise to the left anterior descending and circumflex arteries.

An anterior myocardial infarction is caused by occlusion of the left anterior descending artery.

The coronary sinus is a venous structure that drains blood from the heart and returns it to the right atrium.

Understanding Coronary Circulation

Coronary circulation refers to the blood flow that supplies the heart with oxygen and nutrients. The arterial supply of the heart is divided into two main branches: the left coronary artery (LCA) and the right coronary artery (RCA). The LCA originates from the left aortic sinus, while the RCA originates from the right aortic sinus. The LCA further divides into two branches, the left anterior descending (LAD) and the circumflex artery, while the RCA supplies the posterior descending artery.

The LCA supplies the left ventricle, left atrium, and interventricular septum, while the RCA supplies the right ventricle and the inferior wall of the left ventricle. The SA node, which is responsible for initiating the heartbeat, is supplied by the RCA in 60% of individuals, while the AV node, which is responsible for regulating the heartbeat, is supplied by the RCA in 90% of individuals.

On the other hand, the venous drainage of the heart is through the coronary sinus, which drains into the right atrium. During diastole, the coronary arteries fill with blood, allowing for the delivery of oxygen and nutrients to the heart muscles. Understanding the coronary circulation is crucial in the diagnosis and management of various heart diseases.

Hypokalaemia may be caused by thiazides

Thiazide diuretics can lead to hypokalaemia by stimulating aldosterone production and inhibiting the Na-Cl symporter. This inhibition results in more sodium being available to activate the Na/K-ATPase channel, leading to increased potassium loss in the urine and hypokalaemia.

Thiazide diuretics may also cause other side effects such as hypocalciuria, hypomagnesemia, and hyperlipidemia. The other options that describe the opposite of these disturbances are incorrect.

Thiazide diuretics are medications that work by blocking the thiazide-sensitive Na+-Cl− symporter, which inhibits sodium reabsorption at the beginning of the distal convoluted tubule (DCT). This results in the loss of potassium as more sodium reaches the collecting ducts. While thiazide diuretics are useful in treating mild heart failure, loop diuretics are more effective in reducing overload. Bendroflumethiazide was previously used to manage hypertension, but recent NICE guidelines recommend other thiazide-like diuretics such as indapamide and chlorthalidone.

Common side effects of thiazide diuretics include dehydration, postural hypotension, and electrolyte imbalances such as hyponatremia, hypokalemia, and hypercalcemia. Other potential adverse effects include gout, impaired glucose tolerance, and impotence. Rare side effects may include thrombocytopenia, agranulocytosis, photosensitivity rash, and pancreatitis.

It is worth noting that while thiazide diuretics may cause hypercalcemia, they can also reduce the incidence of renal stones by decreasing urinary calcium excretion. According to current NICE guidelines, the management of hypertension involves the use of thiazide-like diuretics, along with other medications and lifestyle changes, to achieve optimal blood pressure control and reduce the risk of cardiovascular disease.

Full length stripping of the long saphenous vein below the knee is no longer recommended due to its relation to the saphenous nerve, while the short saphenous vein is related to the sural nerve.

The Anatomy of Saphenous Veins

The human body has two saphenous veins: the long saphenous vein and the short saphenous vein. The long saphenous vein is often used for bypass surgery or removed as a treatment for varicose veins. It originates at the first digit where the dorsal vein merges with the dorsal venous arch of the foot and runs up the medial side of the leg. At the knee, it runs over the posterior border of the medial epicondyle of the femur bone before passing laterally to lie on the anterior surface of the thigh. It then enters an opening in the fascia lata called the saphenous opening and joins with the femoral vein in the region of the femoral triangle at the saphenofemoral junction. The long saphenous vein has several tributaries, including the medial marginal, superficial epigastric, superficial iliac circumflex, and superficial external pudendal veins.

On the other hand, the short saphenous vein originates at the fifth digit where the dorsal vein merges with the dorsal venous arch of the foot, which attaches to the great saphenous vein. It passes around the lateral aspect of the foot and runs along the posterior aspect of the leg with the sural nerve. It then passes between the heads of the gastrocnemius muscle and drains into the popliteal vein, approximately at or above the level of the knee joint.

Understanding the anatomy of saphenous veins is crucial for medical professionals who perform surgeries or treatments involving these veins.

The heart is supplied with blood by the coronary arteries, which branch off from the aorta. The right coronary artery supplies blood to the right side of the heart, while the left coronary artery supplies blood to the left side of the heart.

Occlusion, or blockage, of the right coronary artery can cause inferior myocardial infarction (MI), which is indicated on an electrocardiogram (ECG) by changes in leads II, III, and aVF. This type of MI is particularly associated with arrhythmias because the right coronary artery usually supplies the sinoatrial (SA) and atrioventricular (AV) nodes.

The left anterior descending artery (LAD) is one of the two branches of the left coronary artery. It runs along the front of the heart’s interventricular septum to reach the apex of the heart. One or more diagonal branches may arise from the LAD. Occlusion of the LAD can cause anteroseptal MI, which is evident on an ECG with changes in leads V1-V4.

The right marginal artery branches off from the right coronary artery near the bottom of the heart and continues along the heart’s bottom edge towards the apex.

The left circumflex artery is the other branch of the left coronary artery. It runs in the coronary sulcus around the base of the heart and gives rise to the left marginal artery. Occlusion of the left circumflex artery is typically associated with lateral MI.

The left marginal artery arises from the left circumflex artery and runs along the heart’s obtuse margin.

The walls of each cardiac chamber are made up of the epicardium, myocardium, and endocardium. The heart and roots of the great vessels are related anteriorly to the sternum and the left ribs. The coronary sinus receives blood from the cardiac veins, and the aortic sinus gives rise to the right and left coronary arteries. The left ventricle has a thicker wall and more numerous trabeculae carnae than the right ventricle. The heart is innervated by autonomic nerve fibers from the cardiac plexus, and the parasympathetic supply comes from the vagus nerves. The heart has four valves: the mitral, aortic, pulmonary, and tricuspid valves.

Infective endocarditis is most frequently caused by Streptococci viridans, which is commonly found in the oral cavity. This type of infection is often linked to patients with inadequate dental hygiene or those who have undergone dental procedures.

Aetiology of Infective Endocarditis

Infective endocarditis is a condition that affects patients with previously normal valves, rheumatic valve disease, prosthetic valves, congenital heart defects, intravenous drug users, and those who have recently undergone piercings. The strongest risk factor for developing infective endocarditis is a previous episode of the condition. The mitral valve is the most commonly affected valve.

The most common cause of infective endocarditis is Staphylococcus aureus, particularly in acute presentations and intravenous drug users. Historically, Streptococcus viridans was the most common cause, but this is no longer the case except in developing countries. Coagulase-negative Staphylococci such as Staphylococcus epidermidis are commonly found in indwelling lines and are the most common cause of endocarditis in patients following prosthetic valve surgery. Streptococcus bovis is associated with colorectal cancer, with the subtype Streptococcus gallolyticus being most linked to the condition.

Culture negative causes of infective endocarditis include prior antibiotic therapy, Coxiella burnetii, Bartonella, Brucella, and HACEK organisms (Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella). It is important to note that systemic lupus erythematosus and malignancy, specifically marantic endocarditis, can also cause non-infective endocarditis.

The patient’s symptoms strongly suggest Dressler syndrome, which is an autoimmune-related inflammation of the pericardium that typically occurs 2-6 weeks after a heart attack. This condition is characterized by fever, pleuritic pain, and diffuse ST elevation and PR depression on an electrocardiogram. A pleural friction rub can also be heard during a physical exam.

While another heart attack is a possibility, the absence of diffuse ST elevation and the presence of a pleural friction rub make this diagnosis less likely.

A left ventricular aneurysm would present with persistent ST elevation but no chest pain.

Ventricular free wall rupture typically occurs 1-2 weeks after a heart attack and would present with acute heart failure due to cardiac tamponade, which is characterized by raised jugular venous pressure, pulsus paradoxus, and diminished heart sounds.

A ventricular septal defect usually occurs within the first week and would present with acute heart failure and a pansystolic murmur.

Myocardial infarction (MI) can lead to various complications, which can occur immediately, early, or late after the event. Cardiac arrest is the most common cause of death following MI, usually due to ventricular fibrillation. Cardiogenic shock may occur if a large part of the ventricular myocardium is damaged, and it is difficult to treat. Chronic heart failure may result from ventricular myocardium dysfunction, which can be managed with loop diuretics, ACE-inhibitors, and beta-blockers. Tachyarrhythmias, such as ventricular fibrillation and ventricular tachycardia, are common complications. Bradyarrhythmias, such as atrioventricular block, are more common following inferior MI. Pericarditis is common in the first 48 hours after a transmural MI, while Dressler’s syndrome may occur 2-6 weeks later. Left ventricular aneurysm and free wall rupture, ventricular septal defect, and acute mitral regurgitation are other complications that may require urgent medical attention.