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Blood pressure is sensed by baroreceptors (mechanoreceptor sensory neurons) at the carotid sinus and aortic arch, which detect changes (e.g. low BP) based on the degree of stretch. Afferent information is then transmitted to the brain, which leads to reflexive vasoconstriction, an increased heart rate and contractility, increasing SV, CO and BP in turn. Enables assessment of ventricular function, wall motion abnormalities and valvular or structural abnormalities The majority of the blood flow from the left atrium to the left ventricle is passive, with only 30% of flow resulting from left atrial contraction The book is divided into body systems and then each section within the particular body system follows a consistent pattern: Myosin then binds to actin, and contraction occurs via actin–myosin interactions secondary to hydrolysis of adenosine triphosphate (ATP)

Essential hypertension is a multifactorial environmental and genetic condition. There is a greater prevalence of hypertension in first-degree relatives with hypertension, and a high concordance in identical twins. The exact pathophysiology, however, remains undefined. Guidelines: Defining hypertension (NICE 2011, CG127) When considering stress testing, a general rule of thumb should be to consider exercise treadmill tests if the patient has few comorbidities, and pharmacological testing if the patient has underlying ECG abnormalities or is unable to exercise. Vasodilator agents (such as dipyridamole and adenosine) should be used with caution in patients with a history of bronchospasm or carotid stenosis and dobutamine should not be used in patients with a history of ventricular arrhythmia. Cardiac pharmacology Drugs with one fix dosage are the easiest to use; you just take it and forget about it (e.g., vaccines). You don't need to use any dosage calculation formulas!ACS usually results from atherosclerotic plaque rupture, promoting thrombus formation which imposes varying degrees of luminal impingement, precipitating an acute coronary event 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 Definition: stable angina generally occurs due to a fixed narrowing of the coronary arteries, resulting in symptoms typically associated with exertion, emotion, eating and cold weather. The onset of symptoms is predictable and resolves once the stimulus is removed (e.g. resting after exertion). Epidemiology:

Winner of the Young Authors Award at the BMA book awards 2019! Highly Commended in the Medicine category! Ischaemia causes acidosis, decreased ATP production and release of lactate and other chemokines, which stimulate nerve cells in myocytes, producing the sensation of pain Clinical features One might appreciate the beauty of individuality within each heart, perhaps anatomically reflected in the variation observed in arterial supply: 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 In the absence of total thrombotic occlusion, an NSTEMI or unstable angina may commonly develop, and ECG changes (such as ST segment depression and/or T wave inversion) may occur Clinical features:

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Should be recorded 15–30 minutes apart, looking for dynamic changes, and compared with older ECGs if possible Note that individual symptoms may differ based on the aetiological cause of the heart failure and the duration of onset Renal disease (e.g. diabetic nephropathy, glomerulonephritis, polycystic kidneys, renovascular disease) Holding treatments include reducing afterload (e.g. treating with sodium nitroprusside), inotropes, diuretics, ventilation, followed by urgent surgical repair/replacement

All substances are poisons; there is none which is not a poison. The right dose differentiates a poison and a remedy."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. When a person has stable angina, NICE recommends stratifying the probability of coronary artery disease (CAD). Gender (being male), increasing age, typicality of chest pain and associated risk factors (diabetes, smoking, hyperlipidaemia) point to a higher likelihood of CAD. Recommended for patients whose symptoms are still not controlled, and this treatment is particularly recommended for Afro-Caribbean patients

The C wave reflects the tricuspid valve closure, which is not visible on examination. Two descents are present, an X descent (reflecting atrial relaxation) and a Y descent (reflecting ventricular filling). The action potential from the SA node is propagated through the atrial myocytes, which have intercalated discs at a structural level, allowing for the action potential to move freely across both atria Ensuring an adequate cardiac output is vital for organ perfusion. Regulation of CO occurs via modification of heart rate or stroke volume. of the population have a right dominant heart, in which the posterior descending artery originates from the terminal branch of the RCA; whereas the LCX normally supplies the posterior descending artery in a left dominant heart Classically presents with gangrene of the extremities, particularly the toes, if emboli lodge in the lower limbs

Definition • Epidemiology • Risk factors • Differential diagnosis • Etiology • Pathophysiology • Clinical features • Investigations • Management Echocardiography performed before and after exercise (or with dobutamine if exercise is not possible) to assess the myocardium The heart consumes more oxygen per tissue mass than any other organ in the body: myocardial blood supply occurs via the right and left coronary arteries, which arise as the first branches of the aorta at the right and left sinuses of Valsalva, respectively The aim of management is to instigate antiplatelet therapy expeditiously, to re-perfuse the myocardium in STEMI, and to prevent the progression of unstable angina and NSTEMI. The approach to management can be divided into three steps: initial management, advanced management and post-acute management.