Medicine in a Minute

Product Information

The heart is drained mainly by the great, middle and small cardiac veins, and to a lesser extent by other cardiac veins into the coronary sinus, which empties into the right atrium The term ‘angina’ is a commonly used form of ‘angina pectoris’, which is derived from the Latin words angere and pectus which, taken together, mean ‘to strangle the chest’. As one might imagine, angina is typically described by patients as ‘pressure’ or a ‘crushing sensation’ retrosternally. If the pain is ‘stabbing’, positional or sharp, the underlying pathological process is less likely to be ischaemic in nature. Aetiology/pathophysiology: Options include nicotine replacement therapy (NRT), varenicline or bupropion, but none of these should be prescribed together (apart from various subtypes of NRT)

Some patients may present with a hypertensive emergency (accelerated or malignant hypertension) or hypertensive urgency, all of which encompass a severely elevated BP (usually systolic BP >220mmHg or diastolic BP >120mmHg) but are differentiated by the degree of end organ damage. Digoxin inhibits the sodium-potassium pump and is a negative chronotrope and positive inotrope. Patients on digoxin should be monitored for complications (see Section 1.14.1). Atherosclerosis One of the newest agents to emerge in the past few years is the combination tablet valsartan/sacubitril. Two major trials, PARADIGM-HF and PARAMOUNT, were instrumental in establishing that combination therapy with valsartan/sacubitril improves mortality and is far more effective in reducing frequency of admissions than enalapril therapy alone. This was seen in both HFrEF and HFpEF. Sacubitril, the newer agent, is an angiotensin receptor neprilysin inhibitor (ARNI), which exerts its effects by causing increased peptide degradation and promoting natriuresis. 1.4 Hypertension GTN: may be given via the sublingual or buccal route – if minimal to no response, an IV infusion may be considered; note that GTN should be avoided if systolic BP <90mmHg Symptoms observed may be related to an underlying secondary cause (e.g. headaches, palpitations and sweating in phaeochromocytoma)

Clinical features

Transoesophageal echocardiography (TOE) is an alternative, invasive method requiring sedation, which captures images via a probe placed down the oesophagus; TOE has a higher sensitivity and produces higher-quality images, while being particularly effective at imaging the posterior heart Another mechanism that modifies BP is the renin–angiotensin–aldosterone system (RAAS; see Fig. 1.6). When the arterial pressure falls, renin is released from the juxtaglomerular cells of the kidney. Renin converts angiotensinogen (released from the liver) into angiotensin I. Myocardial wall motion is used as a surrogate marker for perfusion, because ultrasound cannot visualise blood flow in the arteries LV aneurysm typically develops after 4–5 weeks, presenting with LV failure, VT and systemic emboli. ECG shows persistent ST elevation. Treat with anticoagulation and/or excision.

The left coronary artery (LCA), which supplies a large surface area of the heart, is subdivided into (see Fig. 1.2): With hypertensive urgency, there is no end organ damage. Accelerated hypertension presents with evidence of hypertensive retinopathy, no worse than grade 3 (e.g. flame haemorrhages, soft exudates) and without papilloedema. The definition of malignant hypertension requires papilloedema. Offer atorvastatin 20mg for primary prevention if estimated 10-year cardiovascular risk using QRISK3 is >10% (note that this is still controversial in some centres) The tricuspid valve orifice is the largest in the heart and its leaflets are supported by chordae tendineae (‘heart strings‘), which link the ventricular aspect of the leaflets to the papillary musclesThis is a relatively small group of drugs. The doses are different depending on the concentration of the drug's active compound in the serum (e.g., vitamin K antagonists, lithium, etc.). This in turn activates calcium-sensitive calcium release channels (also known as ryanodine receptors) in the sarcoplasmic reticulum, which causes sufficient flooding of calcium ions to initiate contraction The presence of two major, or one major and two minor, criteria in the Framingham criteria may also be used to help suggest the diagnosis of heart failure There may be a pericardial rub and evidence of a pericardial effusion on chest X-ray or echocardiography

Ventricular tachycardia and ventricular fibrillation may result in sudden death in up to one-fifth of patients The true interatrial septum is limited to a shallow depression known as the fossa ovalis, which is a remnant of the now closed foramen ovale It is also important to ask about relevant risk factors and family history. Cardiovascular investigations The heart is a four-chambered, muscular structure comprising two atria and two ventricles, which serve to pump deoxygenated (largely venous) blood to the lungs and transport oxygenated (largely arterial) blood to organs and tissues (see Fig. 1.1)Should only be performed if patients are unable to receive PPCI within 90–120 minutes of diagnosis, or where PPCI is contraindicated The intrinsic pacemaker of the heart is usually the sinoatrial node (SA node) because it has the fastest rate of automaticity of all cardiac fibres ( see Fig. 1.4) The joint ESC/ACCF/AHA/WHF task force published the following recommendations for the diagnosis of acute MI in 2012. HPBM: BP measured twice a day, with each entry being the average of 2 readings taken at least 1 minute apart with the patient sitting down Note that individual symptoms may differ based on the aetiological cause of the heart failure and the duration of onset