INTRODUCTIONIschemic heart disease also designated as coronary artery disease refers to a group of closely related syndromes caused by an imbalance between myocardial oxygen demand and blood supply.
ETIOLOGYThe most common cause of imbalance between need and supply of oxygen is atherosclerotic narrowing of the coronary arteries producing ischemia.
RISK FACTORS FOR ATHEROSCLEROSISFixed Risk FactorsAgeMale SexFamily History
OTHER ASSOCIATIONSObesityLack of exerciseHeavy alcoholismDietary factorsOral contraceptivesGoutHigh level of coagulation factor vii & fibrinogenAnxiety & depression
PATHOGENESIS Defective Oxygen Delivery Increased Oxygen Demand IHD becomes symptomatic when there is 75% or more reduction of the lumen of one or more coronary arteries by atherosclerotic plaque. Superimposed Lesions Acute changes in plaque morphology Local platelet aggregation Coronary artery spasm Coronary artery thrombosis
CLASSIFICATION OF IHDStable anginaUnstable anginaMyocardial infarctionSudden cardiac death
WHAT IS ANGINA?Angina is a clinical syndrome characterized by intermittent chest pain caused by reversible myocardial ischemia.The pain is usually substernal or precordial radiating to the shoulder and arm or to the jaw.It lasts for several minutes.
TYPES OF ANGINA STABLE ANGINA VARIANT ANGINA UNSTABLE ANGINA
STABLE ANGINAIt occurs due to increased myocardial oxygen demand during exertion in a patient of narrow coronary arteries.VARIANT ANGINAIt occurs at rest and produced by the reduction of the myocardial blood supply due to coronary artery spasm.UNSTABLE ANGINAIn this type of angina, frequency, severity and duration of episodes are progressively increased. It occurs at rest due to thrombus formation and coronary artery spasm.
DIFFERENCE B/W STABLE & UNSTABLE ANGINASTABLE ANGINA UNSTABLE ANGINA Due to fixed stenosis Due to dynamic stenosis Demand-led ischemia Supply-led ischemia Related to effort Symptoms at rest Symptoms over long Symptoms over short term term
ECGDuring pain ECG showsST –segment depression with or without T wave inversion that reverses after ischemia disappears.Elevation of ST segment in variant angina.The resting ECG may be normal b/w attacks however it may show old MI, heart block or left ventricular hypertrophy.
ETTWhen history is suggestive of angina but ECG normal ETT is performed for diagnosis.Positive test is one in which ST segment is depressed by 1 mm.
INTRODUCTION•MI is death or necrosis of myocardialcells. Myocardial infarction (MI or AMI for acutemyocardial infarction), commonly known as aheart attack, occurs when the blood supply topart of the heart is interrupted.
ETIOLOGYCommonly caused due to occlusion of a coronaryartery following the rupture of a vulnerableatherosclerotic plaque, in the wall of an artery. Theresulting ischaemia and hypoxia, if left untreated fora sufficient period, can cause damage and or death(infarction) of heart muscle tissue.
ETIOPATHOGENESIS1. Mechanism of MI i) Diminished coronary blood flow ii) Increased myocardial demand iii) Cardiac hypertrophy without se of coronary blood flow2. Role of Platelets - rupture of atherosclerotic plaque exposes subendothelial collagen to platelets - aggregation, activation, release of platelets
Pathological Changes Vary according to the age of the infarct Most infarcts occur singly (very less multifocal), 4-10 cm size Most often in left ventricle Subendocardial infarcts produce less well- defined infarcts gross changes than the transmural infarcts.
CLINICAL DIAGNOSISClinical diagnosis is based on SymptomsECG changesElevation of specific serum enzymes
SYMPTOMSOnset is sudden with severe constricting, crushing, burning substernal or precordial pain that radiates to the left shoulder and arm or jaw.Pain is accompanied by sweating, nausea, vomiting or dyspnea.Cardiogenic shock.
ECG Changes ST Segment elevation, follwed by abnormal new Q waves and inverted T wave. Serum EnzymesCreatinine phosphokinaseLactic dehydrogenaseCardiac troponin I & Troponin T.
CHRONIC ISCHEMIC HEART DISEASEChronic IHD some times called ischemic cardiomyopathy is used to describe the development of progressive CHF.It is characterized by multifocal areas of myocardial atrophy and fibrosis secondary to slowly developing coronary atherosclerosis leading to dilatation of cardiac chambers.
CLINICAL FEATURESUsually it remains asymptomatic and progressively CHF develops.Cardiac arrhythmias may occur when scarring involves conduction system.Angina, MI
TYPES OF HEART FAILURE ACUTE HEART FAILURE CHRONIC HEART FAILURE RIGHT AND LEFT HEART FAILURE CONGESTIVE HEART FAILURE FARWARD HEART FAILURE BACKWARD HEART FAILURE CARDIAC ARREST
ACUTE HEART FAILURESudden onset of heart failure without previous symptoms of ischemia or MI.CHRONIC HEART FAILUREGradual onset of heart failure with symptoms of ischemia or MI.CONGESTIVE CARDIAC FAILUREBi ventricular heart failure.
CARDIAC ARRESTComplete cessation of heart function.Conductive system of heart completely block.