Transcript Coronary Heart Disease

Coronary Heart Disease
Coronary Circulation
• Left Coronary Artery
– Anterior descending
– Circumflex
• Right Coronary Artery
– Posterior descending
• Veins
– Small, middle and great cardiac veins
– Coronary sinus
Control of Coronary Blood Flow
• Metabolic
• Endothelial
• Collateral
Chronic Ischemic Heart Disease
•
•
•
•
Most commonly due to atherosclerosis
Vasospasm and thrombosis may contribute
Perfusion pressure may be insufficient
Angina pectoris
Myocardial Infarction
• Abrupt onset
• Pain severe and crushing
• Pain located as for angina, but not relieved
by nitroglycerine
• GI complaints common
• Fatigue and weakness common
Myocardial Infarction
• Tachycardia, anxiety, restlessness, and
feelings of impending doom
• Skin often pale, cool and moist
• 30 - 50% die within first few hours from
ventricular fibrillation
Pathology
• Area of infarction is determined by
coronary artery affected
Myocardial Infarction
Left coronary
artery
Right coronary
artery
Blockage high up
infarcts a large part
of the muscle
Blockage
more distal
infarcts a
smaller spot
Pathology
• Transmural or subendocardial
• Anaerobic respiration
• Ischemic area ceases to function within a
few minutes
• Necrosis after 20 to 40 minutes
• Microvascular injury occurs in 1 hour
following necrosis
Myocardial Infarction
Pathology
• Early reperfusion may reduce level of injury
• Three zones of tissue damage
Myocardial Infarction
Pathology
• Necrotic area replaced with scar tissue
• After 4 - 7 days centre of infarcted area is
soft and yellow
• Rupture often happens now
• Replacement is complete in 7 weeks
• Lacks contractility and conduction
Myocardial Infarction
Classification
• ECG changes
• ST elevation usually indicates acute
myocardial injury
• Significant Q waves usually signify MI
Myocardial Infarction
Classification
• Serum markers signal MI
Myocardial Infarction
Medical Management
• Thrombolytic therapy
• Angioplasty
Myocardial Infarction
Medical Management
• Revascularization interventions
Myocardial Infarction
Congestive Heart Failure
• Pumping ability of the heart becomes
impaired
• Causes:
–
–
–
–
MI
Hypertension
Cardiomyopathies
Excessive work demands
Congestive Heart Failure
• High or low output
• Systolic or diastolic
Stroke volume
(not anatomically
correct)
End diastole
Congestive Heart Failure
• Right or left sided
Right
Left