Ch. 12 IHD, CHF

Question 1

Ischemic heart disease

Answer 1

Beta blockers –> !- myocardial oxygen demand

CCB–> !- vascular resistance , !- contractility –> !- O2 demand

Nitrates –> venous dilation –> !- preload –> !- O2 demand

Antiplatelets (aspirin) –> prevents thrombus formation

Lipid lowering drugs –> !- risk of heart attack in CAD

**unstable angina tx:
Nitroglycerine
Antiplatelet
Anticoagulant

**acute MI tx:
Thrombolytic (tPA)

Question 2

CHF Tx strategy?

Answer 2

1. !- cardiac workload
2. control excess fluid
3. Enhance myocardial contractility

Question 3

Reduction of cardiac workload

Answer 3

Reduce physical activity

ACE-i / ARB (vasodilators): improve sxs, slow progression of HF, prolong survival

Hydralazine + isosorbide dinitrate (vasodilators)

Nitroprusside: in acute HF (reduces both preload and afterload without affecting contractility

Beta-blockers

Nesiritide : a recombinant form of BNP –> diuresis and vasodilation by increasing intracellular cGMP

Question 4

Control of excessive fluid

Answer 4

Lower dietary intake of sodium

Diuretics are used to relieve sxs (exacerbation)

Question 5

Enhancement of contractility

Answer 5

• cardiac glycosides
• sympathomimetics
• phosphodiesterase inhibitors
• ranolazine

Question 6

Cardiac glycosides
Drugs?
MOA?

Answer 6

Drugs: DIGOXIN, DIGITOXIN

MOA: inhibit Na-K-ATPase –> i+ release of intracellular calcium from sarcoplasmic reticulum –> i+ force of contraction of myocytes

Question 7

Cardiac glycosides used in:

Answer 7

Used in: CHF, arrhythmia (i+ sensitivity of the AV node to vagal stimulation)

Question 8

Cardiac glycosides toxicity, side effects:

Answer 8

*low therapeutic index
Toxicity is more common in patients with low serum K ( “dig. And diuretics” )

Toxicity --> 
arrhythmia >>> LIFE THREATENING
Anorexia, nausea, diarrhea
Drowsiness and fatigue
Visual disturbances

Question 9

Sympathomimetics
Drugs?
MOA?

Answer 9

DOBUTAMINE: B1 agonist + some a1 and B2 agonist effects –> at moderate doses increases contractility of heart w/o changing BP or HR. ………… given IV

DOPAMINE: dopamine receptor agonist …… also given IV

Question 10

Sympathomimetics uses:

Answer 10

Acute HF (=exacerbation)

**Dopamine is used when impaired renal function instead of dobutamine to preserve renal blood flow

Question 11

Phosphodiesterase inhibitors Drugs?

MOA?

Answer 11

INAMRINONE (formerly AMRINONE)
MILRINONE

MOA: inhibit cAMP phosphodiesterase in cardiac and vascular muscle –> positive inotropic action + vasodilatory effect

Question 12

RANOLAZINE

Answer 12

New drug. Don’t worry about it
Just know it’s for chronic angina by reducing calcium overload in ischemic heart disease and prevents cell injury and death (aka infarct)