Post on 04-Dec-2015
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ACUTE CORONARY SYNDROME
Unstable Angina
NSTEMI
STEMI
Pathogenesis
Arrhythmias in MI
Rhythm Causes
Sinus bradycardia • ↑ vagal tone • ↓ SA nodal artery perfusion
Sinus tachycardia • Pain and anxiety• Heart failure• Volume depletion• Chronotropic drugs e.g dopamine
Atrial premature beats , AF • Heart failure• Atrial ischaemia
Ventricular premature beats , VT , VF • Heart failure• Ventricular ischaemia
AV block (first , second , third degree) • Inferior MI : ↑ vagal tone and ↓ AV nodal artery flow
• Anterior MI : extensive destruction of conduction tissue
HEART FAILURE
Compensatory Mechanisms
• Frank-Starling Mechanism• Neurohormonal Activations• Ventricular Hypertrophy and Remodeling
RHF LHF
Symptoms • Leg swelling• RUQ pain / discomfort
• Dyspnoea• PND• Orthopnoea • Reduced effort tolerance ,
fatigue
Signs • Jugular venous distension (raised JVP)
• Pedal oedema • Congestive
hepatosplenomegaly
• Diaphoresis • Tachycardia , tachypnoea • Pulmonary rales • Loud P2• S3 gallop (systolic
dysfunction) • S4 (diastolic dysfunction)
Question : Explain the mechanism / pathogenesis of the above signs and symptoms ! , causes of pitting vs non-pitting oedema
• Orthopnoea – redistribution of intravascular blood from the gravity-dependent portions of the body (abdomen and lower extremities) towards the lung after lying down.
• PND - gradual reabsorption into the
circulation o lower extremity interstitial edema after lying down, with subsequent expansion
of intravascular volume and increased venous return to the heart and lungs • Pulmonary congestion + Haemoptysis (rupture of
engorged bronchial veins)
Acute Pulmonary Edema
- Acute heart failure , chronic heart failure
- Interstitial edema , alveolar edema
• Lasix (IV furosemide) – to reduce LV preload , lower pulmonary capillary hydrostatic pressure
• Morphine – to reduce anxiety , venodilator• Nitrates – to reduce preload • Oxygen • Position (sit upright ) • Inotropic drugs (dopamine)
HYPERTENSION
Target Organ Damage
Organ System Manifestations
Heart Left ventricular hypertrophy Heart failure Myocardial ischaemia and infarction
Cerebrovascular Stroke
Vascular Aortic aneurysm and/or dissection Arteriosclerosis
Kidney Nephrosclerosis Renal failure
Retina Arterial narrowing Haemorrhages ,exudates ,papilledema