Cardiovascular diseases-Heart Failure-VI

• Heart is not able to maintain the cardiac output to meet the need of the body tissues or it can do it only at an elevated filling pressure or elevated force of contraction.
• Normal cardiac output depends on preload,afterload and Myocardial contractility.
• Increase in preload and afterload causes left ventricular hypertrophy.It also increases myocardial work.(Starling's law and law of laplace).
• First activation of Renin angiotensin system and sympathetic nervous system,try to compensate cardiac compensation by altering the afterload,preload and myocardial contractility but latter on they become counterproductive and reduce cardiac output by causing increase in peripheral resistance,which further stimulates renin angiotensin system.Angiotensin causes release of aldosterone  that leads to retention of salt and water that causes increase in preload.
• Signs & Symptoms-

1. Dyspnoea
2. Orthopnoea
3. Cheyne-stokes respiration
4. Vomitting
5. Perspiration
6. Nausea
7. Cough 
8. Tachycardia
9. Cold extremities
10. Low B.P
11. Right heart failure leads to Peripheral edema,ascites,Hepatomegaly
12. Left heart failure leads to Pulmonary edema

• Investigations-

1. ECG-St segment elevation with q wave deepening and t wave inversion.
2. X ray shows cardiomegaly
3. Rise in enzyme levels of CK,AST and LDH

• Drug regime-Oxygen therapy,Ace inhibitors/angiotensin antagonist,Diuretics(furosemide),salt restriction,Aspirin and clopodegrel,Beta blockers(only in after correction of heart failure)
• Initially cardiac glycosides were used like digitalis but they were found to be toxic and after the discovery of Ace inhibitors and high ceiling diuretics,the use of digitalis is avoided and mild to moderate cases of heart failure are treated by using Ace inhibitors and diuretics.