Day: March 2, 2024

  Overview Infective endocarditis refers to any infection of the endocardial surface of the heart. Infective endocarditis (IE) can be a life-threatening condition associated with a number of severe complications. It refers to infection of the inner lining of the heart known as the endocardium. Infection of the endocardium may involve one or more heart valves or an intracardiac device (e.g. prosthetic valve). Clinical presentation The clinical presentation of IE is highly variable. There are two major disease courses: Acute, rapidly progressive infection Subacute, or chronic, low-grade infection IE types There are three major types, or categories, of IE: Native valve endocarditis (NVE): normal valves without

Definition & classification Hypertension refers to a persistent elevation of arterial blood pressure. Prevalence is 30% in the UK (defined as adults with BP >140/90 mmHg). It is higher in men than in women before 60 years of age, but equal after this point. Hypertension is a major risk factor for myocardial infarction (MI), stroke and chronic kidney disease (CKD). It is classified into ‘stages’ to help guide management (Based on NICE NG 136 Hypertension guidelines). Aetiology The majority of hypertension is essential (primary), however in a significant number of cases there may be a secondary cause or contributory factor. Primary – 95% No identifiable

Overview Heart failure is a clinical syndrome that results from an inability of the heart to maintain adequate cardiac output. Heart failure (HF) is a clinical syndrome with multiple aetiologies. It is commonly secondary to ischaemic heart disease or hypertensive heart disease. The condition is characterised by progressive shortness of breath, fatigue and fluid overload. Unfortunately, HF is a progressive disorder associated with high morbidity and mortality. Prognosis is generally poor; approximately 50% die within five years. There are many different ways to classify heart failure, which reflect the complexity of the condition: Acute versus chronic Right-sided versus left-sided Systolic (HFrEF) versus

Introduction The heart is able to beat independently, devoid of nervous input. This is achieved through special ‘pacemaker’ cells. Myocardial contraction is dependent on two cell types: Autorhythmic cells (1%): Generate action potentials that drive contractile cells. Do not have a resting potential, instead, they slowly depolarise, hence ‘pacemaker cells’. Contractile cells (99%): Responsible for myocardial contraction. Able to undergo rapid depolarisation, driven by the autorhythmic cells. Conduction system Conduction through the heart is dependent on pacemaker cells organised into key structures. 1. Sinoatrial node (SAN) Location: Spindle-shaped structure located at the junction of the superior vena cava (SVC) and right atrium. Function: The pacemaker of the

Overview Chronic pericarditis refers to long-standing inflammation (>3 months) of the pericardium that usually follows an acute episode. Pericarditis refers to inflammation of the pericardial sac. It may be acute, incessant, or chronic. Acute: an episode of acute pericardial inflammation Incessant: pericardial inflammation lasting > 4-6 weeks but < 3 months Chronic: pericardial inflammation lasting > 3 months Aetiology Chronic inflammation can occur after virtually any pericardial disease process. Almost any cause of acute pericardial inflammation (e.g. viral, radiotherapy, drugs, tuberculosis) can lead to chronic inflammation. Chronic pericarditis rarely occurs after an episode of acute idiopathic pericarditis (~1%). Chronic inflammation is more likely

Overview Cardiomyopathy refers to disease of the heart muscle. The term cardiomyopathy can be very confusing in clinical practice. In very simple terms it means disease of the heart muscle. However, many conditions can affect heart muscle from common cardiovascular diseases (e.g. hypertension, coronary artery disease) to rare genetic conditions. Consequently, a number of definitions have been proposed over the years to help differentiate these many causes and their pathophysiological mechanisms. Definition In 2008, the European Society of Cardiology (ESC) proposed a new definition for cardiomyopathy as ‘A myocardial disorder in which the heart muscle is structurally and functionally abnormal, in

Overview Cardiac tamponade is a life-threatening condition that causes compression of the heart from pericardial content. Cardiac tamponade is a life-threatening condition that is caused by compression of the heart from the accumulation of fluid, blood, clots, or gas within the pericardial space. Compression of the heart prevents adequate filling and contraction, which clinically results in ‘Beck’s triad’ that is a combination of hypotension, venous distension (i.e. raised JVP), and muffled heart sounds. Cardiac tamponade is diagnosed through echocardiography and without urgent needle pericardiocentesis it can lead to cardiac arrest. The pericardium The serous pericardium is a double layered membrane that surrounds the

Introduction The cardiovascular system delivers blood to the body providing both oxygen and nutrients. It is organised into two circuits, pulmonary and systemic. The heart The heart is a dual pump that sits at the centre of the cardiovascular system. It is composed of four chambers: Two atria (left & right) Two ventricles (left & right) Right side: blood is received from the body to be delivered to the lungs.Left side: blood is received from the lungs to be delivered to the body. Blood vessels The flow of blood is mediated by a network of vessels: Arteries – carry oxygenated blood away from the heart. Capillaries –

Overview Atrial fibrillation refers to irregular atrial contraction, caused by chaotic impulses. Atrial fibrillation (AF) is the most common cardiac arrhythmia with an estimated population prevalence of 2.5% in the UK. It is defined as a supraventricular arrhythmia because the abnormality originates above the ventricles in the atria. Classically, there are multiple waves of electrical activity leading to fragmentation of the normal coordinated electrical activity within the atria. This causes the cardiomyocytes to contract independently leading to ‘fibrillation’. AF is characterised by the presence of an irregularly irregular pulse on examination. This is confirmed on a 12-lead ECG or appropriate ECG

Definition & classification Aortic stenosis refers to obstruction of blood flow across the aortic valve, typically due to calcification. Aortic stenosis is the most common valvular disease in the Europe and North America. It affects between 2-7% of those over 65 and symptomatic disease affects men four times more frequently than women. Typically a disease of the elderly, presenting in the seventh or eighth decades of life. Aetiology Calcification is the most common cause of aortic stenosis in the western world. 1. Calcific (degenerative) A degenerative condition caused by inflammation and progressive calcification which limits movement of the aortic valve. Most common cause (80%). Affects

Introduction Aortic regurgitation results from an incompetent aortic valve causing a regurgitant flow of blood in diastole. Aortic regurgitation tends to present between the fourth and sixth decades of life. It affects males three times more commonly than women. Severe disease is seen in < 1% of the population. The most common causes are degenerative disease and congenital bicuspid valve. Epidemiology The prevalence of aortic regurgitation increases with advancing age. In a cohort of the Framingham Heart Study in 1999, in people aged 44-64, a research group found 13% of men and 8.5% of women were affected by trace or greater (i.e. mild, moderate, severe) aortic regurgitation. More significant

Overview Angina refers to classic cardiac pain that is felt when there is a reduction in blood supply to the heart. Angina refers to the central pressing, squeezing, or constricting chest discomfort that is experienced when there is a reduction in blood flow through the coronary arteries. There may be typical radiation to the arm, jaw or neck and it is bought on by physical or emotional exertion and relieved by rest. It typically lasts < 10 minutes. Angina is the main symptom of myocardial ischaemia, which is usually secondary to coronary artery disease (CAD). However, other conditions can cause angina such as coronary spasm,