Antianginals/Tx of Myocardial Ischemia
Order by
66 terms
Terms | Definitions |
|---|---|
 angina pectoris | a specific type of episodic chest pain associated with inadequate perfusion of the myocardium |
| ischemia | an imbalance in the myocardial oxygen supply-demand relationship |
| classical | type of angina that is gradual in its rate of progressive severity; associated with exertion or stress |
| unstable | type of angina characterized by rapidly increasing frequency and severity of attacks; may occur at rest |
| Prinzmetal's Variant | type of angina that commonly occurs at rest in the absence of exertion |
| silent | up to 75% of ischemic episodes may not yield angina pain |
| occlusive CAD | the overwhelming cause of stable angina |
| coronary artery spasm | contraction of the smooth muscle by some condition or agonist which leads to Prinzmetal's Variant angina |
| anemia | high demand for cardiac output (condition) |
| narrowing of arteries | when this happens it usually precedes actual angina pain (esp. >80% reduction in diameter) |
| subendocardium | most poorly perfused (especially during systole) and is at the highest risk for developing ischemia |
| anaerobic metabolism | in angina, energy needs are met this way (glycolysis and lipolysis) |
| left main | blockage of this artery is equivalent to having 3 arteries blocked at the same time |
| ECG | dx: ST segment depression is common although ST segment elevation can occur in variant angina |
| myocardial angiography | dx: detects reduced flow to ischemic area indicating blocked vessels |
| echocardiogram | dx: detects abnormal wall motion |
| myocardial enzymes | dx: creatinine phosphokinase isozyme and troponin. these levels are elevated if there's sufficient cell damage to allow their release |
| angina tx | aim is to restore the balance between oxygen supply and demand at rest, during normal activity, and during exercise if poss. |
| guanylate cyclase, cGMP, nitroglycerin | activates __ activity in arterial and venous smooth muscle, leading to increased levels of __ and higher activity of PKG (NVs) |
| vasodilation | decreases arterial BP, thereby decreasing afterload, the MAJOR therapeutic effect |
| nitrates | lose their effectiveness when overdoses or given too frequently (class) |
| vasodilation, less | increases venous pooling, thereby decreasing preload (__ blood in chambers of heart) |
| vasodilation, coronary | dilates __ arteries |
| ferrous, NO | binds to the __ ion in guanylate cyclase causing its activation |
| SH | low levels of this can cause a tolerance to nitrates |
| nitroglycerin | can also be used to cause relaxation of the sphincter of Oddi in tx of biliary colic (NVs) |
| nitroglycerin | PVC tubing can absorb substantial proportions of this drug and should not be used (NVs) |
| N-acetylcysteine | this is a reduced thiol donor can restore nitrate activity (rotten eggs!) |
| amyl nitrite | volatile liquid which otherwise acts the same as nitroglycerin, faster onset (NVs) |
| amyl nitrite | can be used in cyanide poisoning because it can form methemoglobin (NVs) |
| isosorbide dinitrate | releases NO more slowly than ntg and can be "long-acting" (NV) |
| isosorbide dinitrate | SL form is useful for acute attacks due to rapid onset; PO form is used for prophylaxis, total daily dose should reach 100mg for effectiveness (NV) |
| isosorbide mononitrate | slower release of NO than from dinitrate, recommended to be dosed 20mg bid with 7 hours between doses to reduce tolerance (NV) |
| oxygen demand, B-blockers | act by reducing heart rate and inotropism, thereby decreasing __ (class) |
| B-blockers | useful in combination with nitrates, since they block reflex tachycardia (class) |
| CCBs | inhibit Ca2+ entry via L-type Ca2+ channels (class) |
| L-type | these types of channels allow a large amount of Ca2+ to enter thereby contributing to contraction of cardiac and smooth muscle |
| inactive | CCBs preferentially bind to this state and prolong its duration, causing blockade |
| verapamil | useful in all forms of angina (alone or with nitrates), strong negative inotropic effects (CCB) |
| Phase 2 | decreased calcium entry during this phase of the cardiac action potential causes strong negative inotropic effects and decreased CO |
| verapamil | PO or IV; large first-pass metabolism: clearance is reduced by cimetidine or hepatic disease (CCB) |
| Covera HS | an osmotically-driven, delayed-release form of verapamil. taken at bedtime and delays release for 4-5 hours, producing a peak between 6a and noon, period of high MI occurence (CCB) |
| verapamil | interacts with B-blockers or quinidine, causing additive cardiodepression, decreases digoxin clearance by 60% (CCB) |
| verapamil | can worsen or induce CHF in pts who have too little inotropic drive to the heart (CCB) |
| nifedipine | used in all types of angina as well as hypertension. no cardiac depression, strong vasodilator effect (CCB) |
| nifedipine | current drug of choice for treating Raynaud's disease (CCB) |
| nifedipine | can be safely combined with beta blockers which reduce reflex tachycardia (CCB) |
| nifedipine | side effects: (occur quite often) peripheral edema, "rebound phenomenon" upon cessation of therapy (CCB) |
| diltiazem | side effects: (low, 4% incidence) edema, cardiac arrhythmia, CHF possible (CCB) |
| diltiazem | use caution with beta blockers, can elevate cyclosporine levels increasing its nephrotoxicity (CCB) |
| nimodipine | used to counteract vasospasm immediately following subarachnoid hemorrhage. reduces long-term neurological deficits, but effect mainly seen in men (CCB) |
| israpidine | beneficial effects on HDL and LDL (CCB) |
| felodipine | highly vascular selective (CCB) |
| felodipine | reflex tachycardia common during initial week of therapy and typically increases resting HR about 5-10 BPM (CCB) |
| bepridil | used in angina when other drugs FAIL (CCB) |
| bepridil | also decreases Na+ channel activity (CCB) |
| Caduet | fixed dose combination of amlodipine and atorvastatin |
| amlodipine | QD dosage (T1/2= 35-50hrs), 7-10 days to reach plateau (CCB) |
| amlodipine | can exhibit excessively long T1/2 in patients with hepatic failure (CCB) |
| ranolazine | initially approved only for the tx of "refractory chronic angina", better relief of angina in men vs. women |
| ranolazine | found to inhibit a sodium channel that decreases calcium overload in ischemic cells |
| ranolazine | possible association with Torsade de Pointes arrhythmia, esp. in women |
| nifedipine | only CCB that can be safely admin. with beta blockers |
| amlodipine | nifedipine-like, but with less reflex tachycardia |
| lidoflazine | similar to bepridil, blocks both Na and Ca channels |
| MI, CHF, CCBs | several studies have suggested an increased rate of __ and __ in patients taking short-acting formulations of these drugs (class) |
First Time Here?
Welcome to Quizlet, a fun, free place to study. Try these flashcards, find others to study, or make your own.