ischaemic heart disease pathophysiology and stable angina pectoris

ISCHAEMIC HEART DISEASE Pathophysiology And Stable Angina Pectoris

JD MarxDepartment of Cardiology

University of the Free State

DefinitionThe blood supply to the myocardium

is insufficient to comply fully with physiological needs of the heart

muscle.

Pathophysiology Blood supply - epicardial vessels with

perforating branches Blood flow from epicardium to

endocardium

Pathophysiology Control of blood flow

› Perfusion in diastoly› Oxygen extraction maximal O2 supply can

only be increased by increasing bloodflow› Humeral factors important - ADENOSIN

Oxygen demand Heart rate Blood pressure Myocardial

contractility

Oxygen supply Coronary bloodflow

› Duration of diastoly› Coronary perfusion

pressure› Coronary vasomotor

tone Oxygenation

› Haemoglobin› Oxygen saturation

PathophysiologyFactors influencing myocardial oxygen

supply and demand

SUPPLY DEMAND

O2-Carrying Capacity

Coronary blood flow

Heart Rate Contractility

Systolic wall tension

Vascular resistance Diastolic

phase

Metabolic control

Auto-regulation

Extravascular compressive

forces

Humoral factors

Neuralcontrol

PathogenesisCauses of vessel obstruction

Fixed lesions› Atherosclerosis› Arteritis› Embolization

Dynamic narrowings› Spasm

Pathogenesis

Atherosclerosis is by far the most common cause of obstruction in

patients with IHD

PathogenesisBirth of Plaque

PathogenesisPlaque progression

PathogenesisPlaque rupture

Fixed factors Family history Gender - male Age

Modifiable factors Smoking Hypertension Hypercholesterolemia Diabetes Mellitus Obesity Inactivity Stress

PathogenesisRisk factors for Atherosclerosis

Clinical Presentation

Stable angina pectoris

Acute Coronary Syndromes› Unstable Angina Pectoris› Non ST-segment elevation myocardial infarction› ST-segment elevation myocardial infarction

Arrhythmias

Sudden death

Ischaemic Cardiomyopathy with LV failure

of patients with Ischaemic Heart Disease

Symptomatic Presentation

The patients most often present with chest pain which should clinically evaluated!

of patients with Ischaemic Heart Disease

Symptomatic Presentation

ANGINA PECTORISTypical chest pain caused by ischaemic myocardium

Chest Pain

Clinically patients with angina pectoris present with:

› Stable Angina Pectoris› Acute Coronary Syndromes

Symptomatic PresentationChest Pain

Chest pain resulting from a specific other disease process

› Pericarditis› Pleuritis› Radicular or neural pain› Musculoskeletal pain› Gastroinstestinal pain› Other

Symptomatic PresentationChest Pain

Atypical chest pain› The chest pain is not typical of any clinical

disease entity

› Several special tests necessary to evaluate

Symptomatic PresentationChest Pain

Angina PectorisSTABLE ANGINA PECTORIS

Diagnosis: › Clinical diagnosis: emphasis on history› Angina with stable pain pattern

Confirmed by:› Resting ECG› Stress ECG› Isotope perfusion study› Coronary angiography

Angina PectorisExercise Stress Test

Angina PectorisIsotope Stress Test

Exercise Rest

Angina PectorisAngiogram

LCA RCA

Angina PectorisTREATMENT

Conservative treatment: General treatment

› Aspirin

Anti-anginal medication› Nitrates› β-blockers› Calcium antagonists

Disease Modifying Therapy› Statins› ACE Inhibitors

Interventional treatment: Coronary angioplasty ( PTCA ) Coronary Artery Bypass Graft Surgery ( CABG )

Thank you