In profound heart failure, ventricular assist systems (VAS) have been used to maintain the systemic circulation and promote recovery of the failing heart. The authors' data suggest that the heart may not recover sufficiently if the patient needs left ventricular assist beyond 10 days. Recently, the authors treated six patients who were supported by VAS more than 3 weeks and were weaned from VAS. Four of six patients were weaned from VAS and continue well, despite marginal cardiac function. In the other two patients, the natural heart did not sustain stable recovery, but their general conditions made them fit to be candidates for heart transplantation. Based on these data, long-term support should be considered to promote recovery of heart function with the use of VAS for profound heart failure.

Adolescent↗

PubMedDate not supplied

Recovery of cardiac function by long-term left ventricular support in patients with end-stage cardiomyopathy.

Effects of long-term left ventricular (LV) support on end-stage cardiomyopathy patients is unclear. We applied our LV assist system (LVAS) to six heart transplant candidates, aged 17 to 49, with dilated cardiomyopathy, including one dilated phase hypertrophied cardiomyopathy. LVAS was installed between the left atrium and the ascending aorta, and the pump was positioned parecorporeally. In all patients, their general condition improved, and their pump flows were kept at 4 to 5 L/min. Exercise was started after stabilization of their general condition under constant pump flow. Natural heart size and function were examined by echocardiography. In the beginning of assist, all patients showed impaired cardiac function and LV dilation. During LV assist, systolic function measured by ejection time improved in all patients. Left ventricular end-diastolic dimension (LVDd), showed a remarkable decrease in two patients, who were weaned from LVAS after 3 months of support. They are doing well more than 1 year and 3 years after removal; peak VO2 levels (ml/min/kg) were 30 at 1.2 years and 27 at 2.7 years after removal. In the other four patients, however, LVDd had no remarkable changes, and three could not be weaned from LVAS. The last was discontinued from LVAS after 5 months of support because of infection and died 2 months after removal. From this experience, long-term LVAS may provide the chance for recovery of the natural heart in patients with end-stage cardiomyopathy. The patients whose hearts showed remodeling were able to be weaned from LVAS, and their heart function maintained in good condition for several years.

Adolescent↗

PubMedDate not supplied

Practical assessment of natural heart function using echocardiography in mechanically assisted patients.

Left ventricular assist systems (LVAS) can maintain the systemic circulation of patients with acute, profound heart failure. The assessment of natural heart (NH) function, however, is difficult in the clinical setting. The authors introduced a new index, heart rate-corrected ejection time/left atrial pressure (ETc/LAP) using echocardiography to evaluate NH function in 15 adult patients on the original LVAS for greater than 2 days. Bypass flow (BF) was gradually decreased according to the recovery of NH. Five patients were weaned from LVAS within 15 days, and LV function was well maintained (Group 1). Another six patients were weaned from LVAS within 21 days but died within 2 weeks (Group 2). The other four patients died on LVAS without recovery of NH (Group 3). In Group 1 patients, ejection time/pre-ejection period (ET/PEP) with LVAS assist increased continuously. In Groups 2 and 3, ET/PEP increased slowly and reached a plateau at approximately 10 days or remained low. Group 1 patients reached an ETc/LAP of 35 +/- 10 on LVAS within 7 days. Group 2 and Group 3 patient values were 18 +/- 2 (p less than 0.05) and 9 +/- 6 (p less than 0.01), respectively, on the seventh day. Based on these data, this new index provides an estimate of global NH function and a prediction of the probability of NH recovery.

Adult↗

PubMedDate not supplied

Thrombus in a natural left ventricle during left ventricular assist: another thromboembolic risk factor.

Systemic thromboembolism is one of the serious complications during use of a left ventricular assist system (LVAS). The authors' original LVAS has excellent antithrombogenicity to reduce this risk, but thrombus formation in a natural left ventricle (LV) is another risk factor for systemic embolization. We used our LVAS in 22 patients. Of these, LV wall motion was studied in 15, and a smoke-like echo disclosed thrombus in the LV in eight. When LVAS sufficiently supported the systemic circulation, LV wall motion was irregular upon closure of the aortic valve. Upon recovery of LV function and decrease of LVAS flow, the smoke-like echo diminished and LV thrombus decreased in one, but LV thrombus remained unchanged or increased in seven. Systemic administration of antithrombotic agents had an unclear effect. Seven of eight patients with LV thrombus on echo died during or after LVAS. In these seven, a high incidence of LV thrombus (71%), and systemic embolism to the brain (29%) or kidney (86%), were revealed at necropsy. We subsequently used local heparinization to prevent LV thrombus formation. One patient with a smoke-like echo had no evidence of LV thrombus or systemic embolism. During LV assist, careful management of the LVAS, and intra-LV heparinization should be considered to reduce the risk of thrombus formation in the natural LV.

Adult↗