Safe and Unsafe Hypertension Medications During Pregnancy

Gestational hypertension, which is characterized by new hypertension after 20 weeks without significant proteinuria, can be treated with various medications. However, not all hypertension medications are safe during pregnancy. Thiazide diuretics, such as bendroflumethiazide and thiazide-like diuretics like indapamide, should be avoided as they can cause complications in the fetus. Angiotensin receptor blockers (ARBs) like losartan and angiotensin-converting enzyme (ACE) inhibitors like ramipril can also affect fetal blood pressure control and should be avoided unless essential. Labetalol is recommended as the first-line treatment for gestational hypertension, with methyldopa and nifedipine as other safe options. Hypertension is defined as a diastolic BP >90 mmHg or a systolic BP >140 mmHg.

Left bundle branch block is typically indicative of underlying ischaemic or structural heart disease and is never considered normal. However, there are several normal variants that can appear on an ECG, such as sinus arrhythmia, right axis deviation (common in tall and thin individuals), left axis deviation (common in short, obese individuals), and partial right bundle branch block. Additionally, athletes may exhibit certain normal variants due to their high vagal tone, such as sinus bradycardia and 1st degree atrioventricular block.

Normal Variants in Athlete ECGs

Athletes may exhibit certain ECG changes that are considered normal variants. These include sinus bradycardia, junctional rhythm, first degree heart block, and Mobitz type 1 (Wenckebach phenomenon). Sinus bradycardia refers to a slower than normal heart rate originating from the sinus node, which is the natural pacemaker of the heart. Junctional rhythm occurs when the heart’s electrical impulses originate from the junction between the atria and ventricles, rather than the sinus node. First degree heart block is a delay in the electrical conduction between the atria and ventricles, resulting in a prolonged PR interval on the ECG. Mobitz type 1, also known as Wenckebach phenomenon, is a type of heart block where there is a progressive lengthening of the PR interval until a beat is dropped. These ECG changes are considered normal in athletes and do not necessarily indicate any underlying cardiac pathology.

When a patient presents with symptoms of thoracic aortic dissection and is stable, CT angiography is the preferred diagnostic test. This imaging technique provides a clear view of the aorta and helps plan surgical intervention if necessary. In cases of proximal aortic dissection, inter-arm blood pressure measurements may reveal a difference of over 20 mmHg, with the right arm showing higher pressure due to its proximity to the heart. The absence or reduction of femoral pulses on one or both sides is also a common finding. While a chest x-ray may show signs associated with aortic dissection, it is not specific enough for diagnosis. Transesophageal echocardiography (TOE) is used to confirm the diagnosis if CT angiography is inconclusive or if the patient is unstable. Transthoracic echocardiography (TTE) is less sensitive and specific than TOE for detecting aortic dissection.

Understanding Aortic Dissection: Classification, Investigation, and Management

Aortic dissection is a serious medical condition that requires prompt diagnosis and management. It is classified according to the location of the tear in the aorta, with type A affecting the ascending aorta in two-thirds of cases, and type B affecting the descending aorta distal to the left subclavian origin in one-third of cases. The DeBakey classification further divides aortic dissection into type I, which originates in the ascending aorta and propagates to at least the aortic arch, and type II, which is confined to the ascending aorta. Type III originates in the descending aorta and rarely extends proximally but will extend distally.

To diagnose aortic dissection, imaging studies such as chest x-ray and CT angiography of the chest, abdomen, and pelvis are essential. Transoesophageal echocardiography (TOE) may be more suitable for unstable patients who cannot undergo CT scanning. Management of type A aortic dissection requires surgical intervention, but blood pressure should be controlled to a target systolic of 100-120 mmHg while awaiting surgery. Type B aortic dissection can be managed conservatively with bed rest and IV labetalol to reduce blood pressure and prevent progression.

Complications of aortic dissection depend on the location of the tear. Backward tears can lead to aortic incompetence/regurgitation and myocardial infarction, while forward tears can cause unequal arm pulses and blood pressure, stroke, and renal failure. Endovascular repair of type B aortic dissection may have a role in the future. It is important to remember that patients may present acutely and be clinically unstable, so the choice of investigations and management should take this into account.

Clopidogrel inhibits platelet activation by blocking the binding of adenosine diphosphate (ADP) to the platelet P2Y12 receptor. This is achieved by preventing the activation of the glycoprotein GPIIa/IIIb. It is recommended by NICE for secondary prevention following a cerebrovascular accident or in peripheral arterial disease. It can also be used in combination with aspirin for the management of ischaemic heart disease or for patients undergoing percutaneous transluminal coronary intervention.

Tirofiban and abciximab are drugs that block glycoprotein IIIb/IIIa receptors, preventing platelet aggregation by blocking fibrinogen from binding to platelet receptors. These drugs are used under specialist supervision only for the treatment of acute ST elevation myocardial infarction or during percutaneous transluminal coronary intervention.

Hirudin, produced by leeches, blocks thrombin receptors. Bivalirudin, a hirudin analogue, is used for the acute management of acute coronary syndrome or during PCI.

Aspirin inhibits thromboxane production by blocking the enzyme cyclooxygenase (COX).

Heparin binds to antithrombin III, activating it, which reduces the activity of thrombin and factor Xa. Heparin is an anticoagulant and plays a role in the treatment of venous thromboembolism, while clopidogrel is an anti-platelet agent.

The 2014 NICE guidelines recommend using the QRISK2 tool to identify patients over 40 years old who are at high risk of CVD, with a 10-year risk of 10% or greater. A full lipid profile should be checked before starting a statin, and atorvastatin 20mg should be offered first-line. Lifestyle modifications include a cardioprotective diet, physical activity, weight management, limiting alcohol intake, and smoking cessation. Follow-up should occur at 3 months, with consideration of increasing the dose of atorvastatin up to 80 mg if necessary.

Heart failure patients with a left ventricular ejection fraction of less than or equal to 40% and symptoms no more severe than class III according to the New York Heart Association functional classification may benefit from digoxin in terms of reducing hospitalization. However, it does not have an impact on mortality. While increasing the dosage of furosemide may provide relief from fluid overload symptoms, it does not affect mortality.

Non-Drug Management for Chronic Heart Failure

Chronic heart failure is a condition that requires long-term management to improve symptoms and reduce hospitalization. While medication is often the first line of treatment, non-drug management options are also available. Two such options are cardiac resynchronization therapy and exercise training.

Cardiac resynchronization therapy involves biventricular pacing for patients with heart failure and wide QRS. This therapy has been shown to improve symptoms and reduce hospitalization in patients with NYHA class III heart failure. By synchronizing the heart’s contractions, this therapy can improve the heart’s pumping ability and reduce symptoms such as shortness of breath and fatigue.

Exercise training is another non-drug management option for chronic heart failure. While it may not reduce hospitalization or mortality rates, it has been shown to improve symptoms. Exercise can help improve the heart’s ability to pump blood and increase overall fitness levels. This can lead to a reduction in symptoms such as fatigue and shortness of breath, allowing patients to engage in daily activities with greater ease.

Overall, non-drug management options such as cardiac resynchronization therapy and exercise training can be effective in managing chronic heart failure. These options can improve symptoms and quality of life for patients, reducing the need for hospitalization and improving overall health outcomes.

If a patient has poorly controlled hypertension and is already taking an ACE inhibitor, calcium channel blocker, and a standard-dose thiazide diuretic, and their potassium level is above 4.5mmol/l, the best option is to add an alpha- or beta-blocker. According to NICE guidelines, this patient has resistant hypertension, which is stage 4 of the NICE flowchart for hypertension management. Spironolactone can also be introduced at this stage, but only if the patient’s serum potassium is less than 4.5mmol/l, as spironolactone is a potassium-sparing diuretic. Indapamide is not suitable for someone who is already taking a thiazide diuretic like bendroflumethiazide. Furosemide is typically used for hypertension management in patients with heart failure or kidney disease, which is not present in this case. Hydralazine is primarily used for emergency hypertension management or hypertension during pregnancy, not for long-term management.

NICE Guidelines for Managing Hypertension

Hypertension, or high blood pressure, is a common condition that can lead to serious health problems if left untreated. The National Institute for Health and Care Excellence (NICE) has published updated guidelines for the management of hypertension in 2019. Some of the key changes include lowering the threshold for treating stage 1 hypertension in patients under 80 years old, allowing the use of angiotensin receptor blockers instead of ACE inhibitors, and recommending the use of a calcium channel blocker or thiazide-like diuretic in addition to an ACE inhibitor or angiotensin receptor blocker.

The guidelines also provide a flow chart for the diagnosis and management of hypertension. Lifestyle advice, such as reducing salt intake, caffeine intake, and alcohol consumption, as well as exercising more and losing weight, should not be forgotten and is frequently tested in exams. Treatment options depend on the patient’s age, ethnicity, and other factors, and may involve a combination of drugs.

NICE recommends treating stage 1 hypertension in patients under 80 years old if they have target organ damage, established cardiovascular disease, renal disease, diabetes, or a 10-year cardiovascular risk equivalent to 10% or greater. For patients with stage 2 hypertension, drug treatment should be offered regardless of age. The guidelines also provide step-by-step treatment options, including adding a third or fourth drug if necessary.

New drugs, such as direct renin inhibitors like Aliskiren, may have a role in patients who are intolerant of more established antihypertensive drugs. However, trials have only investigated the fall in blood pressure and no mortality data is available yet. Patients who fail to respond to step 4 measures should be referred to a specialist. The guidelines also provide blood pressure targets for different age groups.

For a newly diagnosed patient of black African or African-Caribbean origin with hypertension, adding a calcium channel blocker (CCB) such as nifedipine is recommended as the first-line treatment. This is because ACE inhibitors and ARBs are less effective in patients of these ethnicities. Lifestyle advice alone is not sufficient if the patient’s average blood pressure reading on ambulatory monitoring is greater than 150/95 mmHg. Ramipril is not the first-line option for this patient population, and Losartan is a second-line option after CCBs.

NICE Guidelines for Managing Hypertension

Hypertension, or high blood pressure, is a common condition that can lead to serious health problems if left untreated. The National Institute for Health and Care Excellence (NICE) has published updated guidelines for the management of hypertension in 2019. Some of the key changes include lowering the threshold for treating stage 1 hypertension in patients under 80 years old, allowing the use of angiotensin receptor blockers instead of ACE inhibitors, and recommending the use of a calcium channel blocker or thiazide-like diuretic in addition to an ACE inhibitor or angiotensin receptor blocker.

The guidelines also provide a flow chart for the diagnosis and management of hypertension. Lifestyle advice, such as reducing salt intake, caffeine intake, and alcohol consumption, as well as exercising more and losing weight, should not be forgotten and is frequently tested in exams. Treatment options depend on the patient’s age, ethnicity, and other factors, and may involve a combination of drugs.

NICE recommends treating stage 1 hypertension in patients under 80 years old if they have target organ damage, established cardiovascular disease, renal disease, diabetes, or a 10-year cardiovascular risk equivalent to 10% or greater. For patients with stage 2 hypertension, drug treatment should be offered regardless of age. The guidelines also provide step-by-step treatment options, including adding a third or fourth drug if necessary.

New drugs, such as direct renin inhibitors like Aliskiren, may have a role in patients who are intolerant of more established antihypertensive drugs. However, trials have only investigated the fall in blood pressure and no mortality data is available yet. Patients who fail to respond to step 4 measures should be referred to a specialist. The guidelines also provide blood pressure targets for different age groups.

Urgent synchronised DC cardioversion is necessary when heart failure is observed as an adverse sign.

Management of Peri-Arrest Tachycardias

The Resuscitation Council (UK) guidelines for the management of peri-arrest tachycardias have been simplified in the 2015 update. The previous separate algorithms for broad-complex tachycardia, narrow complex tachycardia, and atrial fibrillation have been replaced by a unified treatment algorithm. After basic ABC assessment, patients are classified as stable or unstable based on the presence of adverse signs such as hypotension, pallor, sweating, confusion, or impaired consciousness. If any of these signs are present, synchronised DC shocks should be given, up to a maximum of three shocks.

The treatment following this is based on whether the QRS complex is narrow or broad and whether the rhythm is regular or irregular. For broad-complex tachycardia, a loading dose of amiodarone followed by a 24-hour infusion is given if the rhythm is regular. If the rhythm is irregular, expert help should be sought as it could be due to atrial fibrillation with bundle branch block, atrial fibrillation with ventricular pre-excitation, or torsade de pointes.

For narrow-complex tachycardia, vagal manoeuvres followed by IV adenosine are given if the rhythm is regular. If unsuccessful, atrial flutter is considered, and rate control is achieved with beta-blockers. If the rhythm is irregular, it is likely due to atrial fibrillation, and electrical or chemical cardioversion is considered if the onset is less than 48 hours. Beta-blockers are usually the first-line treatment for rate control unless contraindicated. The full treatment algorithm can be found on the Resuscitation Council website.

Torsades de pointes can be treated with IV magnesium sulfate.

Torsades de Pointes: A Life-Threatening Condition

Torsades de pointes is a type of ventricular tachycardia that is associated with a prolonged QT interval. This condition can lead to ventricular fibrillation, which can cause sudden death. There are several causes of a prolonged QT interval, including congenital conditions such as Jervell-Lange-Nielsen syndrome and Romano-Ward syndrome, as well as certain medications like antiarrhythmics, tricyclic antidepressants, and antipsychotics. Other causes include electrolyte imbalances, myocarditis, hypothermia, and subarachnoid hemorrhage.

The management of torsades de pointes involves the administration of intravenous magnesium sulfate. This can help to stabilize the heart rhythm and prevent further complications.