Left ventricular reduction

Left Ventricular Reduction Surgery Using Partial Left Ventriculectomy (the Batista Procedure)... 

The principle of left ventricular reduction according to Batista is to improve myocardial waU tension by reducing ventricular size based on Laplaces law. This is done by direct resection of a variable myocardial portion (partial left ventriculectomy) from the anterior, lateral, or posterior wall. In most patients having undergone this procedure, a circumscribed scar is visualized at the site of the ventriculotomy. In patients with left ventricular aneurysms, linear aneurysmal resection in which the aneurysmal sac is incised and the vital myocardium approximated by simple linear suture has become rare. The most widely used alternative technique is the Dor procedure where the aneurysm is incised and phcated by a purse-string suture around its neck. The remaining defect is covered with a synthetic patch over which the... 

ACE inhibitors lower the elevated blood pressure in humans with a concomitant decrease in total peripheral resistance. Cardiac output is increased or unchanged heart rate is unchanged urinary sodium excretion is unchanged and potassium excretion is decreased. ACE inhibitors promote reduction of left ventricular hypertrophy. 

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. 

P-Blockers and ACE inhibitors are also indicated for post-myocardial infarction for the reduction of cardiovascular morbidity and mortality, as are aldosterone antagonists, in post-myocardial infarction patients with reduced left ventricular systolic function and diabetes or signs and symptoms of heart failure.2,48... 

Chymostatin-sensitive Il-generating enzyme Carvedilol Post-Infarct Survival Control in Left Ventricular Dysfunction Trial Collaborative Study Captopril Trial ( The Effect of Angiotensin-Converting Enzyme Inhibition on Diabetic Nephropathy ) calcium channel blocking agents Candesartan in Heart Failure Assessment of Reduction in Morbidity and Mortality Trial congestive heart failure, but the latest recommendations use HF for heart failure chronic kidney disease cardiac output... 

The progenitor cells of the kidney produce 90% of the hormone erythropoietin (EPO), which stimulates red blood cell (RBC) production. Reduction in nephron mass decreases renal production of EPO, which is the primary cause of anemia in patients with CKD. The development of anemia of CKD results in decreased oxygen delivery and utilization, leading to increased cardiac output and left ventricular hypertrophy (LVH), which increase the cardiovascular risk and mortality in patients with CKD. 

The answer is a. (Hardman, pp 762-764.) Experimentally, nitrates dilate coronary vessels. This occurs in normal subjects, resulting in an overall increase in coronary blood flow. In arteriosclerotic coronaries, the ability to dilate is lost, and the ischemic area may actually have less blood flow under the influence of nitrates. Improvement in the ischemic conditions is the result of decreased myocardial oxygen demand because of a reduction of preload and afterload. Nitrates dilate both arteries and veins and thereby reduce the work of the heart. Should systemic blood pressure fall, a reflex tachycardia will occur. In pure coronary spasm, such as Prinzmetal s angina, the effect of increased coronary blood flow is relevant, while in severe left ventricular hypertrophy with minimal obstruction, the effect on preload and afterload becomes important. 

Pharmacology The principal pharmacological action of nitrates is relaxation of the vascular smooth muscle and consequent dilation of peripheral arteries and especially the veins. Dilation of the veins promotes peripheral pooling of blood and decreases venous return to the heart, thereby reducing left ventricular end-diastolic pressure and pulmonary capillary wedge pressure (preload). Arteriolar relaxation reduces systemic vascular resistance, systolic arterial pressure, and mean arterial pressure (afterload). Dilation of the coronary arteries also occurs. The relative importance of preload reduction, afterload reduction, and coronary dilation remains undefined. 

Myocardial hypertrophy Myocardial hypertrophy has been reported in association with the administration of tacrolimus and generally is manifested by echocardiographically demonstrated concentric increases in left ventricular posterior wall and interventricular septum thickness. Hypertrophy has been observed in infants, children, and adults. This condition appears reversible in most cases following dose reduction or discontinuance of therapy. 

Evaluation of left ventricular ejection fraction (LVEF) is recommended prior to administration of the initial dose of mitoxantrone. Subsequent LVEF evaluations are recommended if signs or symptoms of CFIF develop, and prior to all doses administered to patients who have received a cumulative dose of 100 mg/m or more. Do not administer mitoxantrone to MS patients who have received a cumulative lifetime dose of 140 mg/m or more, or those with either LVEF of less than 50% or a clinically significant reduction in LVEF. 

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. 

The more recent use of aggressive medical therapy with beta blockers, ACE-inhibitors, aspirin, and HMG Co A reductase inhibitors has had a profound benefit on those with coronary artery disease and reduced LVEF. To that end, revascularization still plays an important role in mortality reduction. In the Studies of Left Ventricular Dysfunction (SOLVD) database, CABG does improve survival compared to more modern use of medical therapy, with a 25% mortality risk reduction as well as an intriguing 46% risk reduction of sudden death [91]. This benefit improved as LVEF decreased, thus providing evidence that revascularization may stabilize heart function, reduce abnormal remodeling, and thus reduce the propensity to arrhythmogenicity. 

Reduction of the left ventricular outflow obstruction and antiarrhythmic activity underlying the beneficial effect of verapamil. 

According to Laplace s law, a reduction in ventricular pressure and heart size results in a decrease in the myocardial wall tension that is required to develop a given intraventricular pressure and therefore decreases oxygen requirement. Since blood flow to the subendocardium occurs primarily in diastole, the reduction in left ventricular end diastolic pressure induced by nitroglycerin reduces extravascular compression around the subendocardial vessels and favors redistribution of... 

It is characterized by severe, persisting pain, shock and hypotension with possible development of arrhythmias and is due to severe depression of systolic cardiac performance, systolic arterial pressure is below 80 mm Hg, low cardiac index, ventricular filling pressure is elevated and pulmonary edema may or may not be evident. The most frequent cause is infarction involving more than fourty percent of the left ventricular myocardiam, leading to a severe reduction in left ventricular contractility contradictively and failure of the left ventricular pump. 

Decreased venous return to the heart and the resulting reduction of intracardiac volume are important beneficial hemodynamic effects of nitrate. Arterial pressure also decreases. Decreased intraventricular pressure and left ventricular volume are associated with decreased wall tension (Laplace relation) and decreased myocardial oxygen requirement. In rare instances, a paradoxical increase in myocardial oxygen demand may occur as a result of excessive reflex tachycardia and increased contractility. 

Abrahamsson K, Melander M, Eriksson BO, Holme E, Jodal U, Jonasson A. Transient reduction of human left ventricular mass in carnitine depletion induced by antibiotics containing pivalic acid. Br Heart J 1995 74 656-9. 

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