Left ventricular

Amiodarone dilates arteriolar vascular smooth muscle, especiady coronary arteries, and thus exhibits antianginal effects. Its effects on the peripheral vasculature to decrease resistance leads to a decrease in left ventricular stroke work and a decrease in myocardial oxygen consumption. The dmg rarely produces hypotension that requires discontinuation of the dmg (1,2). 

The heart, a four-chambered muscular pump has as its primary purpose the propelling of blood throughout the cardiovascular system. The left ventricle is the principal pumping chamber and is therefore the largest of the four chambers in terms of muscle mass. The efficiency of the heart as a pump can be assessed by measuring cardiac output, left ventricular pressure, and the amount of work requHed to accomplish any requHed amount of pumping. 

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. 

Fig. 2. Fibrin sealant spray application at site of left ventricular aneurysm repair to facilitate hemostasis (arrow points to adhesive).

Kuznetsova T, Staessen JA, Thijs L et al (2004) European Project On Genes in Hypertension (EPOGH) Investigators. Left ventricular mass in relation to genetic variation in angiotensin II receptors, renin system genes, and sodium excretion. Circulation 110 2644-2650... 

Systolic pressure, or maximum blood pressure, occurs during left ventricular systole. Diastolic pressure, or minimum blood pressure, occurs during ventricular diastole. The difference between systolic and diastolic pressure is the pulse pressure. While diastolic blood pressure has been historically been used as the most relevant clinical blood pressure phenotype, it has now been clearly established that systolic blood pressure is the more important clinical predictor for cardiovascular morbidity and mortality. More recently, additional attention is focussed on the importance of pulse pressure, i.e. the blood pressure amplitude, as a predictive factor for cardiovascular disease. 

Discuss heart failure in relationship to left ventricular failure, right ventricular failure, neurohormonal activity, and treatment options. 

Left ventricular dysfunction, also called left ventricular systolic dysfunction, is the most common fonn of heart failure and results in decreased cardiac output and decreased ejection fraction (the amount of blood that the ventricle ejects per beat in relationship to the amount of blood available to eject). Typically, the ejection fraction should be greater than 60%. With, left... 

Until recently, the cardiotonics and a diuretic were the treatment of choice for HE However, other dragp such as the angiotensin-converting enzyme (ACE) inhibitors, and beta blockers have become the treatment of choice during the last several years. See Figure 39-1 for an example of a method of determining treatment for left ventricular systolic dysfunction. See Chapters 23, 42, and 46 for more information on the beta blockers, ACE inhibitors, and diuretics, respectively. 

Managing Heart Failure in Patients with Left Ventricular Systolic Dysfunction ... 

FIGURE 39-1. Management of left ventricular systolic dysfunction. (Adapted from Ammon, S [2001], Managing patients with heart failure, AJN 101 [12] 35.)... 

Which of tire following is commonly associated with left ventricular systolic dysfunction ... 

Hypertrophic cardiomyopathy (HCM) is characterized by abnormal left ventricular thickening. The left ventricular septum is the most common site of involvement. Pathologically, the disease is characterized by myocardial fiber disarray. The myocardium may exhibit extensive scarring and disorganization of interstitial and intercellular tissue (Elstein et al., 1992). The severity of HCM depends on the age of the patient, as well as the extent of the disarray. Patients with HCM have variable... 

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

Enalaprilat 4-6 hour Up to 30 minute 1.25-40 mg q6 hour Hyperkalemia, renal failure, cough, anaphylaxis Useful in left ventricular dysfunction, variable response, should not be given in pregnancy... 

It is important to obtain a baseline EKG and cardiac enzymes to evaluate the possibility of an acute myocardial infarction. The short-term (2-4 weeks) stroke risk after acute myocardial infarction (AMI) is 2.5%. Stroke is usually an early (within 14 days) complication of AMI and is more common in anterior wall (4—12%) than in inferior wall infarction (1%). Approximately 40% of patients with an anterior wall myocardial infarction develop left ventricular thrombus. 

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