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PubMed2003

[Guidelines for the evaluation and management of chronic heart failure].

The Japanese Circulation Society have long been involved in the development of practice guidelines designed to assist physicians in the management of chronic heart failure. Importantly, as our population ages, the incidence of chronic heart failure and its mortality rate will continue to increase. Furthermore, recent advances in our understanding of the pathophysiology of chronic heart failure and new developments in the therapy of this disorder have greatly expanded the information base which to make decisions. The guidelines for the evaluation and management of chronic heart failure were developed by cardiovascular specialists and were based primarily on a comprehensive review of published reports. Furthermore, these guidelines are based on the assumption that the resources necessary to provide this care readily available.

Adrenergic beta-Antagonists↗
PubMed2005

Thirty-five years of mechanical circulatory support at the Texas Heart Institute: an updated overview.

Since the 1960s, the Texas Heart Institute has been intimately involved in the development of mechanical circulatory support devices (for example, ventricular assist devices, aortic counterpulsation pumps, and total artificial hearts) for both short- and long-term use. Here, we review the varied clinical experience with these technologies at the Texas Heart Institute over the last 35 years.

Assisted Circulation↗
PubMedDate not supplied

Nursing care of a patient requiring prolonged mechanical circulatory support.

Four cardiac transplant candidates were supported with ventricular assist devices for periods ranging from 53 to 90 days (mean, 75 days). The patients were men who ranged in age from 36 to 49 years (mean, 44.5 years). Two patients had Pierce-Donachy biventricular assist devices (BVADs) and two patients had Novacor left ventricular assist systems (LVASs). Complications included infection (3 patients), development of antibodies (2 patients), bleeding (2 patients), and pump inflow obstruction (1 patient). All patients were maintained on an anticoagulation regimen which included warfarin and dipyridamole. They were extubated and ambulatory for most of the period of mechanical support. Thromboembolic complications did not develop in any of these patients, and they did not acquire infections which involved the mediastinum. They were successfully transplanted and discharged 11 to 25 days after transplantation. Although major complications were common in this small group of patients, all four patients achieved hemodynamic stability and became excellent candidates for cardiac transplantation. With proper patient selection and meticulous nursing care, current mechanical circulatory support technology is capable of maintaining patients consistently for periods of greater than 50 days.

Adult↗
PubMed1989

Temporary mechanical ventricular support: Part 1.

Temporary mechanical circulatory support is currently indicated in postcardiotomy cardiogenic shock and if necessary as a bridge to cardiac transplantation. This support is presently required in 1% of adult patients undergoing cardiac surgery. Cardiac function and quality of life in long-term survivors following hospital discharge has been excellent.

Assisted Circulation↗
PubMed1989

Radionuclide assessment of the natural heart ejection fraction before and after LVAD implantation.

Complete pressure unloading of the ventricles can preserve ischemically damaged myocardium. Most clinical left heart assist device (LVAD) systems used after ischemic injury of the heart apply atrial cannulation which does not ensure pressure unloading. In order to assess the effect of the implantation of an intracorporeal LVAD on the function of the natural heart, we determined the ejection fraction (EF) in four male Holstein calves (90-105 kg) before and after insertion of a Cleveland Clinic pneumatic LVAD. A gated blood pool scan was obtained with a gamma camera after injection of 40 mCi Tc-labelled albumin. The animals were restrained in a sling to avoid movement artifacts. All animals showed a drop of 65 +/- 12% to 42 +/- 14% EF in the first postoperative (p.o.) week. Left ventricular output did not maintain sufficient blood pressure as assessed by pump-off tests. Systolic blood pressure dropped from 122 +/- 6.5 mm Hg to 81 +/- 6 mm Hg without pump support on the morning of the first p.o. day. Apical coring and possible restrained heart movement by the implanted LVAD may lead to impaired myocardial function that renders the individual LVAD dependent until adaptative corrections take place.

Animals↗
PubMed1988

Cardiac assist devices.

Mechanical circulatory assistance is making the transition from an investigational technique to standard clinical practice, especially for post-cardiotomy shock. History, techniques, medications, complications, and results of mechanical assistance are reviewed. Promising trends for the future are presented.

Assisted Circulation↗
PubMedDate not supplied

Cardiac disuse atrophy during LVAD pumping.

The authors investigated morphologic changes of myocardial tissue of goats supported with a long-duration left ventricular assist device (LVAD). The bypass flow rates of the LVAD were kept at maximum levels (about 80% of total cardiac output) in four goats for 30 days, and at a limited flow rate (around 60%) in one goat each for 30 and 90 days. Morphometric studies using light and electron microscopy were performed on the left ventricles, comparing them to those in the four control studies. The results disclosed: 1) relative volume densities of the myocytes and interstitial tissue in the myocardium were unchanged; 2) cross-sectional areas of the myocytes in the maximum bypass cases were significantly reduced in comparison with pre-experimental data; 3) relative myocyte volumes, calculated by myocytes and nuclear volume densities, were reduced in three goats in the maximum bypass group; and 4) relative volume density of myofibrils was reduced in the maximum and 90 day bypass groups, whereas that of mitochondria was reduced only in the 90 day bypass case. These results indicate that LVADs cause cardiac atrophy which correlates with bypass flow rate and duration of assistance.

Animals↗
PubMedDate not supplied

Hemodynamic effects of a counterpulsation device implanted on the ascending aorta in severe cardiogenic shock.

A valveless, single orifice counterpulsation device (CD) with maximum stroke volume of 100 ml was implanted on the ascending aorta of nine dogs. Its pneumatic driver was gaited by the ECG to provide aortic diastolic augmentation, with a stroke volume of 60-70 ml. In the same animals a 20 ml intraaortic balloon (IAB) was placed into the descending aorta. An attempt was made to evaluate the effectiveness of the CD on severe cardiogenic shock and to compare its hemodynamic effects with those of the IABP. Severe cardiogenic shock was induced by coronary artery ligation, propranolol administration, and fluid infusion and was characterized by a LVEDP of 22.2 +/- 6.4 mmHg, ASP less than 70 mmHg and greater than or equal to 30 mmHg, and a reduction of CI by 71.7%. The CD had a significant beneficial effect in all measured parameters. The LVEDP decreased by a mean of 44.3% (P less than 0.001) below control value, and the AEDP by 60.2% (P less than 0.001). The PADA increased by 108.5% (P less than 0.001), and the CI by 155.8% (P less than 0.004). The IABP did not significantly change any of the hemodynamic variables. In conclusion, the CD has significant salutary hemodynamic effects in severe cardiogenic shock where IABP is ineffective.

Animals↗
PubMedDate not supplied

Left ventricular oxygen consumption and organ blood flow distribution during pulsatile ventricular assist.

One goal of left ventricular assistance is the reduction of left ventricular myocardial oxygen consumption while delivering adequate organ blood flow. The effect of assist device operation control mode and uptake cannulation method on the achievement of this goal was studied in six acutely prepared calves with healthy hearts. All combinations of left ventricular assistance significantly reduced the myocardial oxygen consumption; the reduction was independent of control mode. During ventricular assistance, regional organ blood flow distribution and myocardial endocardial/epicardial blood flow ratio were not different from values during the control, unassisted condition. Regardless of the left ventricular assist device uptake method or operational control mode, significant reduction in myocardial oxygen consumption was achieved while maintaining organ blood flow distribution.

Animals↗
PubMedDate not supplied

Simplified method of hemofiltration in ventricular assist device patients.

Hypervolemia frequently complicates the management of ventricular assist device (VAD) patients as a result of increased intravenous fluid administration and concomitant renal dysfunction. Although acute hemodialysis (AHD) can be used to treat such patients, it requires additional equipment, vascular access cannulations, and personnel. Moreover, hypotension during AHD may occur as a result of rapid shifts in intravascular volume. From January 1987 to March 1988, we treated nine selected VAD patients who had hypervolemia and acute renal failure with a simplified hemofiltration technique. A continuous arteriovenous hemofiltration (CAVH) cartridge was connected from the outflow circuit of a centrifugal blood pump to a large-bore central venous catheter. With CAVH, gradual removal of 272 cc/hour of ultrafiltrate was accomplished for periods up to 241 hours. No episodes of hypotension, thromboembolism, or other deleterious effects occurred. In our series, the CAVH technique was effective in treating hypervolemia in selected VAD patients.

Acute Kidney Injury↗