Left ventricular function

Diuretics have become the cornerstone of all treatment regimens of CHF (III—II3). They can reheve symptoms of pulmonary and peripheral edema. In mild CHF, the thia2ide-type diuretics are adequate unless the GFR falls below 30 ml,/min, as compared to 120 ml,/min in normal subjects. Diuretics improve left ventricular function in CHF due in part to decrease of preload. Indapamide has been shown to cause reduction of pulmonary arterial pressure and pulmonary wedge pressure. 

Several clinical trials have been conducted with streptokinase adrninistered either intravenously or by direct infusion into a catheterized coronary artery. The results from 33 randomized trials conducted between 1959 and 1984 have been examined (75), and show a significant decrease in mortaUty rate (15.4%) in enzyme-treated patients vs matched controls (19.2%). These results correlate well with an ItaUan study encompassing 11,806 patients (76), in which the overall reduction in mortaUty was 19% in the streptokinase-treated group, ie, 1.5 million units adrninistered intravenously, compared with placebo-treated controls. The trial also shows that a delay in the initiation of treatment over six hours after the onset of symptoms nullifies any benefit from this type of thrombolytic therapy. Conversely, patients treated within one hour from the onset of symptoms had a remarkable decrease in mortaUty (47%). The benefits of streptokinase therapy, especially in the latter group of patients, was stiU evident in a one-year foUow-up (77). In addition to reducing mortahty rate, there was an improvement in left ventricular function and a reduction in the size of infarction. Thus early treatment with streptokinase is essential. 

Arnold RJ, Kaniecki DJ, Frishman WH. Cost-effectiveness of antihypertensive agents in patients with reduced left ventricular function. Pharmacotherapy 1994 14 178-84. 

During hospitalization, a measurement of left ventricular function, such as an echocardiogram, is performed to identify patients with low ejection fractions (less than 40%) who are at high risk of death following hospital discharge. 

Echo Moderately reduced left ventricular function, left ventricular ejection fraction 35%... 

FIGURE 6-6. Decision algorithm for long-term ventricular rate control with oral drug therapy for patients with paroxysmal or permanent atrial fibrillation, bpm, beats per minute CCB, calcium channel blocker (diltiazem or verapamil) HF, heart failure LV, left ventricular function LVEF, left ventricular ejection fraction. (Algorithm adapted with permission from Tisdale JE, Moser LR. Tachyarrhythmias. In Mueller BA, Bertch KE, Dunsworth TS, et al. (eds.) Pharmacotherapy Self-Assessment Program, 4th ed. Kansas City American College of Clinical Pharmacy 2001 ... 

Hirsch, A., Gervine, E., Nakso, S., Come, P., Silverman, K. and Grossman, W., The effect of caffeine on exercise tolerance and left ventricular function in patinets with coronary heart disease. Annals of Internal Medicine 110, 593-598, 1989. 

Anaesthetized studies using MI2 data capture system with additional measurement of blood flow in selected vascular beds, cardiac output, respiratory and left ventricular function. 

Horowitz SF, Fischbein A, Matza D Evaluation of right and left ventricular function in hard metal workers. Br J Ind Med 45 742-746, 1988... 

The first 24-hour dose may be individualized for each patient however, in controlled clinical trials, mean daily doses greater than 2100 mg were associated with an increased risk of hypotension. The initial infusion rate should not exceed 30 mg/min. Based on the experience from clinical studies, a maintenance infusion of up to 0.5 mg/min can be cautiously continued for 2 to 3 weeks regardless of the patient s age, renal function, or left ventricular function. There has been limited experience in patients receiving amiodarone IV for more than 3 weeks. 

Edema Edema, mild to moderate, typically associated with arterial vasodilation and not due to left ventricular dysfunction, occurs in 10% to 30% of patients receiving nifedipine. It occurs primarily in the lower extremities and usually responds to diuretics. In patients with CHF, differentiate this peripheral edema from the effects of decreasing left ventricular function. 

Iskandrian AS, Hakki AH, Kane SA, Goel IP, Mundth ED, Hakki AH et al. Rest and redistribution thallium-201 myocardial scintigraphy to predict improvement in left ventricular function after coronary arterial bypass grafting. Am I Cardiol 1983 51 1312-1316... 

Christian TF, Behrenbeck T, Pellikka PA, Huber KC, Chesebro JH, Gibbons RJ. Mismatch of left ventricular function and infarct size demonstrated by technetium-99m isonitrile imaging after reperfusion therapy for acute myocardial infarction identification of myocardial stunning and hyperkinesia. J Am Coll Cardiol 1990 16 1632-1638... 

Cornel JH, Bax JJ, Elhendy A, Maat AP, Kimman GJ, Geleijnse ML et al. Biphasic response to dobutamine predicts improvement of global left ventricular function after surgical revascularization in patients with stable coronary artery disease imphcations of time course of recovery on diagnostic accuracy. J Am Coll Cardiol 1998 31 1002-1010... 

Santana CA, Shaw LJ, Garcia EV, Soler-Peter M, Candell-Riera J, Grossman GB et al. Incremental prognostic value of left ventricular function by myocardial ECG-gated FDG PET imaging in patients with ischemic cardiomyopathy. J Nucl Cardiol 2004 11 542-550... 

Gerson MC, Craft LL, McGuire N, Suresh DP, Abraham WT, Wagoner LE. Carvedilol improves left ventricular function in heart failure patients with idiopathic dilated cardiomyopathy and a wide range of sympathetic nervous system function as measured by iodine 123 metaiodoben-zylguanidine. J Nucl Cardiol 2002 9 608-615... 

Mulder P, Barbier S, Chagraoui A, et al. Long-term heart rate reduction induced by the selective 1(f) current inhibitor ivabradine improves left ventricular function and intrinsic myocardial structure in congestive heart failure. Circulation 1674 109 1674-9. 

Bakker PF, Meijburg HW, de Vries JW, et al. Biventricular pacing in end-stage heart failure improves functional capacity and left ventricular function. J. Interv. Card. Electrophysiol. 2000 4 395 404. 

The pump s major advantages are its ease of use and wide availability. Frequent lABP use is speculated to have been a factor affecting the low 30-day mortality of the medically treated group in the SHOCK (Should we emergently revascularize Occluded Coronaries for cardiogenic shocK ) trial [7]. However, other studies suggest that the lABP only delays death and does not prevent it [8]. The lABP s main limitations are its short duration of use and requirement for partially intact left ventricular function [9]. 

Potential advantages of the Impella compared to the TandemHeart include miniature size (13 F versus 17 F), ease of insertion, maintenance of limb perfusion, and low bleeding rate. Retrograde insertion of the Impella is a technique familiar to most cardiologists. However, the Impella 2.5 can generate only 2.5 1 of cardiac output and hence is suitable for patients with some intrinsic left ventricular function. The TandemHeart, however, can generate an output of 3.5 1/min and can almost completely replace left ventricle function. 

In a study by Zohlnhofer et al. [140], 56 AMI patients were assigned to receive G-CSF treatment after successful percutaneous coronary intervention. Those patients were compared with 58 patients assigned to receive a placebo. The G-CSF treatment did not influence infarct size, left ventricular function, or coronary restenosis, and G-CSF was not associated with adverse outcomes. 

Tse et al. [130] have reported that transendocar-dial injection of autologous BMMNCs in eight patients with severe ischemic heart disease led to preserved left ventricular function. At 3-month follow-up, heart failure symptoms and myocardial perfusion had improved, especially in the ischemic region as shown by cardiac MRI. 

With regard to left ventricular function, cardiac stem cell therapy is well tolerated overall. No proar-rhythmic effects have been observed to date with ABMMNC therapy, although other deleterious effects are possible. Early concerns about abnormal transdifferentiation and tumorigenesis have subsided, but the potential for accelerated atherogen-esis remains, given the limited clinical experience... 

Chen SL, Fang WW, Ye F, Liu YH, Qian J, Shan SJ, Zhang JJ, Chunhua RZ, Liao LM, LinS, Sun JP. Effect on left ventricular function of intracoronary transplantation of autologous bone marrow mesenchymal stem cell in patients with acute myocardial infarction. Am J Cardiol 2004 94 92-95. 

Assmus B, Honold J, Lehmann R, Pistorius K, Hoffmann WK, Martin H, Schachinger V, Zeiher AM. Transcoronary transplantation of progenitor cells and recovery of left ventricular function in patients with chronic ischemic heart disease results of a randomized controlled trial. Circulation 2004 110(Suppl III) 238. 

Torp-Pedersen C, Kober L. Effect of ACE inhibitor tran-dolapril on life expectancy of patients with reduced left-ventricular function after acute myocardial infarction. TRACE Study Group. TrandolaprU Cardiac Evaluation. Lancet 1999 354(9172) 9-12. 

Fox K, Ferrari R, Yusuf S, Borer JS. Should angiotensinconverting enzyme-inhibitors be used to improve outcome in patients with coronary artery disease and preserved left ventricular function Eur Heart J 2006 27(18) 2154-7. 

The cornerstone of therapy for ventricular fibrillation is electrical deflbrillation. In the acute setting, defibrination is first-line therapy. Intravenous bretylium can occasionally contribute to conversion, but this is infrequent. In the management of out-of-hospital cardiac arrest, high-dose epinephrine (5 mg intravenously) improves the rate of successful resuscitation in patients with asystole, but not in those with ventricular fibrillation, when compared with the standard dose of 1 mg. Vasopressin (40 U intravenously) may more effective than 1 mg intravenous epinephrine in out-of-hospital patients with ventricular fibrillation that is resistant to electrical defibrillation. The OPTIC smdy (see Connolly et al., 2006) showed that amiodarone plus jS-blocker is superior than sotalol or jS-blocker alone for reducing ICD shocks in patients with reduced left ventricular function and history of sustained VT, VF, or cardiac arrest. 

As with other antiarrhythmic drugs, moricizine has proarrhythmic activity, which may manifest as new ventricular ectopic beats or a worsening of preexisting ventricular arrhythmias. These effects are most common in patients with depressed left ventricular function and a history of congestive heart failure. Cardiovascular ef-... 

---