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At least 613 records · Page 34Linked to original sources
PubMedDate not supplied

HeartPatch implanted direct cardiac compression: effect on coronary flow and flow patterns in acute heart failure sheep.

A novel HeartPatch direct cardiac compression (DCC) device has been shown to effectively restore circulatory parameters in sheep with acute heart failure (HF). Its effect on the coronary circulation and myocardial perfusion, however, remains uncertain. The effect of DCC assist on coronary artery blood flow (CABF) and its patterns in acute HF sheep were examined in this study. Ten sheep (51 +/- 6 kg) were implanted with a heart patch on each of the left ventricular and right ventricular free walls 1 week before study. Stable HF [cardiac output (CO) at 51 +/- 8% of baseline] induced by intravenous esmolol resulted in CABF decreasing to 53 +/- 16% of baseline (p < 0.001). DCC device activation did not alter CABF (54 +/- 15% of baseline, N.S.) but was accompanied by increases in both peak antegrade and retrograde flow velocity (161 +/- 75%, p < 0.001 and 413 +/- 377%, p < 0.001). A shift in the proportion of flow occurring in diastole (%DF) also was observed: baseline, 81 +/- 9%; HF, 82 +/- 6%; DCC assist, 121 +/- 16% (p < 0.001). Despite significant changes in coronary artery flow pattern resulting from DCC of the failing heart, total antegrade coronary flow was maintained. These findings suggest that myocardial perfusion is not compromised by DCC.

Animals↗
PubMedDate not supplied

Hemodynamic and pressure-volume responses to continuous and pulsatile ventricular assist in an adult mock circulation.

This study investigated the hemodynamic and left ventricular (LV) pressure-volume loop responses to continuous versus pulsatile assist techniques at 50% and 100% bypass flow rates during simulated ventricular pathophysiologic states (normal, failing, recovery) with Starling response behavior in an adult mock circulation. The rationale for this approach was the desire to conduct a preliminary investigation in a well controlled environment that cannot be as easily produced in an animal model or clinical setting. Continuous and pulsatile flow ventricular assist devices (VADs) were connected to ventricular apical and aortic root return cannulae. The mock circulation was instrumented with a pressure-volume conductance catheter for simultaneous measurement of aortic root pressure and LV pressure and volume; a left atrial pressure catheter; a distal aortic pressure catheter; and aortic root, aortic distal, VAD output, and coronary flow probes. Filling pressures (mean left atrial and LV end diastolic) were reduced with each assist technique; continuous assist reduced filling pressures by 50% more than pulsatile. This reduction, however, was at the expense of a higher mean distal aortic pressure and lower diastolic to systolic coronary artery flow ratio. At full bypass flow (100%) for both assist devices, there was a pronounced effect on hemodynamic parameters, whereas the lesser bypass flow (50%) had only a slight influence. Hemodynamic responses to continuous and pulsatile assist during simulated heart failure differed from normal and recovery states. These findings suggest the potential for differences in endocardial perfusion between assist techniques that may warrant further investigation in an in vivo model, the need for controlling the amount of bypass flow, and the importance in considering the choice of in vivo model.

Adult↗
PubMed1993

Use of biventricular circulatory support as bridge to simultaneous heart and kidney transplantation.

A 64-year-old man with dilated cardiomyopathy and chronic renal insufficiency (without dialysis) was admitted in cardiogenic shock urgently requiring a circulatory biventricular assist device (Thoratec). Twenty-nine days later we performed orthotopic cardiac and heterotopic renal transplantations with organs from the same donor. Postoperatively secondary renal insufficiency occurred due to rejection of the graft, bleeding ulcer with hypovolemic shock, and peritonitis due to Streptococcus faecalis and Candida. In the postoperative course only one rejection of the cardiac graft was detected. The patient was discharged after 4 months, resuming a normal life.

Assisted Circulation↗
PubMed2005

[Blood activation during long-term mechanical circulatory support].

Mechanical circulatory support has become an approved treatment option for patients with cardiogenic shock or end-stage heart failure. However, recipients of heart assist devices are prone to high incidences of bleeding, thrombo-embolic and infectious complications. The occurrence of these complications is favoured by systemic alterations of coagulation and fibrinolysis, inflammation and immune responses. Several studies have evaluated these pathophysiological changes in patients undergoing long term circulatory support with pulsatile devices. However, the systemic consequences of the more recently introduced rotary blood pumps remain largely unknown. The present review focuses on the systemic consequences of long term circulatory support with pulsatile and non-pulsatile devices.

Assisted Circulation↗
PubMed1997

Permanent mechanical circulatory support with an implantable left ventricular assist device.

A 67-year-old man had end-stage ischemic cardiomyopathy. He had had two previous coronary bypass operations and a previous left ventricular aneurysmectomy. In December 1995 he underwent vented-electric HeartMate LVAD insertion as an alternative to transplantation. He was discharged from the hospital 13 days after the operation, and 5 months postoperatively he had returned to New York Heart Association functional class II.

Aged↗
PubMed1988

Haemolysis test of non-pulsatile and pulsatile impeller blood pumps.

Non-pulsatile and pulsatile impeller blood pumps have been developed. The non-pulsatile pump was compared with the Shanghai and Sarns 7000 roller pumps for haemolysis. Similarly, the pulsatile pump was compared with a pneumatic diaphragm pump and the Polystan pulsatile pump. In each test, one impeller pump and the pump it was being compared with were connected to two identical circulatory systems with the same volume of fresh citrated porcine blood, delivered at the same pressure and flow for several hours. Every half hour the free haemoglobin was measured and the index of haemolysis (IH) calculated. The mean IH of the non-pulsatile impeller pump was about 18% of the Shanghai roller pump and 29% of the Sarns 7000 roller pump; the IH of the pulsatile impeller pump was 16% of the diaphragm pump and 8% of the Polystan pulsatile pump.

Assisted Circulation↗