Iraqi Board Cardiology key terms

The relationship showing that increased ventricular filling (preload) stretches myocardial fibres, increasing force of contraction and stroke volume up to a physiological limit; in heart failure the curve is flattened and shifted downward.

The degree of ventricular stretch at end-diastole, determined by ventricular filling volume and pressure; clinically estimated by end-diastolic volume or pressure and influenced by venous return and atrial contraction.

The load against which the ventricle must eject blood during systole; determined by systemic vascular resistance, arterial pressure, ventricular wall thickness and outflow tract obstruction, and inversely related to stroke volume.

The proportion of end-diastolic ventricular volume ejected during systole, calculated as stroke volume divided by end-diastolic volume; a key measure of systolic function, normal typically 55–70%.

The volume of blood pumped by the heart per minute, equal to stroke volume multiplied by heart rate; a central determinant of systemic oxygen delivery and a target of haemodynamic assessment.

The volume of blood ejected by the ventricle in a single contraction, normally about 70 mL; determined by preload, afterload and contractility, and used to calculate cardiac output.

The average arterial pressure over the cardiac cycle, approximated as diastolic pressure plus one-third of the pulse pressure; reflects perfusion pressure to vital organs.

The sequence of membrane potential changes in cardiac myocytes, with phases 0–4 describing depolarisation, plateau and repolarisation; differences between nodal and non-nodal cells underlie automaticity and conduction.

The primary cardiac pacemaker located at the junction of the superior vena cava and right atrium; generates impulses at 60–100 per minute and is influenced by autonomic tone.

A structure at the junction of the atria and ventricles that delays impulse conduction, allowing ventricular filling before contraction; it also serves as a secondary pacemaker.

A hormonal cascade activated by reduced renal perfusion or sodium delivery, producing angiotensin II and aldosterone, causing vasoconstriction and sodium retention; a key target in hypertension and heart failure therapy.

A G-protein-coupled receptor on cardiac and vascular cells; beta-1 stimulation increases heart rate and contractility, while beta-2 stimulation causes vasodilation and bronchodilation; blocked by beta-blockers.

A drug that blocks beta-adrenergic receptors, reducing heart rate, contractility and renin release; used in ischaemic heart disease, heart failure, arrhythmias and hypertension.

A drug inhibiting the conversion of angiotensin I to angiotensin II, reducing vasoconstriction and aldosterone release; first-line therapy for heart failure with reduced ejection fraction and hypertension, especially with diabetes or proteinuria.

A drug blocking aldosterone receptors, promoting natriuresis and reducing myocardial fibrosis; indicated in heart failure with reduced ejection fraction and resistant hypertension, with monitoring of potassium and renal function.

A drug inhibiting HMG-CoA reductase, lowering LDL cholesterol and reducing cardiovascular events; used in primary and secondary prevention, with intensity chosen according to risk.

A chronic inflammatory disease of arteries characterised by lipid-rich plaque formation within the intima, leading to luminal narrowing, plaque rupture and thrombotic occlusion.

A spectrum of conditions caused by acute myocardial ischaemia, including ST-elevation myocardial infarction, non-ST-elevation myocardial infarction and unstable angina; requires urgent risk stratification and reperfusion when indicated.

Acute myocardial infarction with ST-segment elevation on ECG, usually from complete coronary artery occlusion; requires emergency reperfusion by primary percutaneous coronary intervention or fibrinolysis.

A cardiac structural protein released into blood when myocytes are injured; high-sensitivity assays are the preferred biomarker for diagnosing myocardial infarction, with serial measurement and interpretation alongside clinical findings.

A catheter-based procedure to treat coronary artery stenosis, usually with balloon angioplasty and stent placement; the preferred reperfusion strategy for ST-elevation myocardial infarction when available in a timely manner.

An invasive X-ray technique using contrast medium to visualise the coronary arteries; the reference standard for defining coronary anatomy and guiding revascularisation decisions.

The ratio of distal coronary pressure to aortic pressure during maximal hyperaemia, used to assess the functional significance of a coronary stenosis; values of 0.80 or less generally indicate revascularisation benefit.

A clinical syndrome of heart failure with left ventricular ejection fraction of 40% or less; treated with disease-modifying drugs including renin-angiotensin system inhibitors, beta-blockers, mineralocorticoid receptor antagonists and SGLT2 inhibitors.

Heart failure with left ventricular ejection fraction of 50% or more, typically with diastolic dysfunction and elevated filling pressures; management focuses on decongestion, comorbidities and SGLT2 inhibitors.

Impaired ventricular relaxation or increased stiffness, leading to elevated filling pressures at normal volumes; assessed by echocardiographic Doppler indices and common in heart failure with preserved ejection fraction.

Ultrasound imaging of the heart providing real-time assessment of chamber size, wall motion, valve function and haemodynamics; transthoracic and transoesophageal approaches are central to diagnosis and monitoring.

Dysfunction of one or more cardiac valves causing stenosis or regurgitation, leading to pressure or volume overload; diagnosis and timing of intervention rely on symptoms and imaging severity criteria.

Narrowing of the aortic valve orifice, usually from calcific degeneration, causing outflow obstruction; severe symptomatic disease is an indication for valve replacement by surgery or transcatheter approach.

Backflow of blood from the left ventricle to the left atrium during systole due to valve leaflet or apparatus dysfunction; chronic severe disease can lead to volume overload and heart failure.

A catheter-based procedure to implant a prosthetic aortic valve without open-heart surgery; an alternative to surgical replacement in selected patients with severe aortic stenosis.

A supraventricular arrhythmia with disorganised atrial electrical activity and irregular ventricular response; associated with stroke risk and managed with rate or rhythm control and anticoagulation.

A clinical score estimating stroke risk in atrial fibrillation using factors such as heart failure, hypertension, age, diabetes, prior stroke and vascular disease; guides the decision to start anticoagulation.

Therapeutic inhibition of blood clotting, used to prevent thromboembolism in atrial fibrillation, mechanical valves and venous thrombosis; options include vitamin K antagonists and direct oral anticoagulants.

A procedure using radiofrequency or cryoenergy delivered via catheters to destroy arrhythmogenic tissue; used for rhythm control in atrial fibrillation and for curative treatment of many supraventricular tachycardias.

An invasive procedure using intracardiac catheters to record electrical activity and to induce and map arrhythmias; guides ablation and assesses conduction system disease.

Impaired conduction from atria to ventricles, classified as first, second (Mobitz I or II) or third degree; symptomatic high-grade block may require permanent pacemaker implantation.

The time from the start of the QRS complex to the end of the T wave on ECG, reflecting ventricular depolarisation and repolarisation; prolongation increases the risk of torsades de pointes.

A polymorphic ventricular tachycardia associated with a prolonged QT interval, characterised by twisting of the QRS complexes around the baseline; treated with magnesium and correction of causes.

Persistently elevated arterial blood pressure, generally defined as office systolic pressure of 140 mmHg or more or diastolic pressure of 90 mmHg or more; a major modifiable risk factor for cardiovascular and renal disease.

The main cholesterol-carrying lipoprotein in blood and a causal factor in atherosclerosis; its lowering by statins or other agents reduces cardiovascular risk, with targets set by overall risk.

Structural abnormalities of the heart or great vessels present at birth, ranging from simple defects to complex lesions; survival into adulthood is now common, requiring lifelong specialist follow-up.

Pulmonary arterial hypertension with reversed or bidirectional shunting caused by a long-standing left-to-right shunt; characterised by cyanosis and poor prognosis, and requires avoidance of pregnancy and careful management.

Elevated mean pulmonary arterial pressure of more than 20 mmHg at rest, classified by cause into groups including arterial, left heart, lung disease and thromboembolic; diagnosis requires right heart catheterisation.

Invasive measurement of pressures and flows in the right heart and pulmonary circulation using a balloon-tipped catheter; essential for diagnosing pulmonary hypertension and assessing haemodynamics.

Inflammation of the pericardium causing chest pain, often pleuritic and relieved by sitting forward, with pericardial friction rub and ECG changes; most cases are idiopathic or viral and managed with anti-inflammatory therapy.

An abnormal accumulation of fluid in the pericardial space, detected by echocardiography; can be asymptomatic or progress to tamponade depending on volume and rate of accumulation.

A life-threatening condition in which pericardial fluid raises intrapericardial pressure, impairing ventricular filling and reducing cardiac output; presents with hypotension, raised jugular venous pressure and muffled heart sounds.

Needle aspiration of pericardial fluid for diagnosis or emergency treatment of tamponade, usually guided by echocardiography; carries risks including arrhythmia and myocardial puncture.