Skeletal muscle ventricles: Left ventricular apex to aorta configuration

Lu, Huiping; Fietsam, Robert; Hammond, Robert L.; Nakajima, Hidehiro; Mocek, Frank W.; Thomas, Gregory A.; Ruggiero, Renato; Nakajima, Hisako O.; Colson, Michael; Stephenson, Larry W.

doi:10.1016/0003-4975(93)90477-y

Cited by 28 publications

(12 citation statements)

References 22 publications

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“…4 It has been used extensively in the assessment of cardiac assist devices. 5 Another potential benefit of an increased MADP is an improvement in coronary artery blood flow. The mean diastolic blood flow through the left anterior descending coronary artery was therefore measured.…”

Section: Indices Of the Effectiveness Of Counterpulsationmentioning

confidence: 99%

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Counterpulsation From the Skeletal Muscle Ventricle and the Intraaortic Balloon Pump in the Normal and Failing Circulations

et al. 2006

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Background-The intra-aortic balloon pump (IABP) is the device that is in most common use to provide cardiovascular support. A skeletal muscle ventricle (SMV) was configured to produce counterpulsation in the thoracic aorta similar to that obtained with an IABP. The hemodynamic effects of an IABP and a SMV in the same animal and in both normal and failing circulations were assessed. Methods and Results-SMVs were connected to and IABPs were placed in the thoracic aorta of 12 anesthetized pigs.Hemodynamic parameters during the IABP-or the SMV-assisted beat were compared with those during the preassist beat. Acute heart failure was induced in 6 of the pigs by snaring the left anterior descending coronary artery (LAD). The hemodynamic effects of the IABP and the SMV were then reassessed. In the assisted cycles, SMV activation increased the mean aortic diastolic pressure (MADP) by 26.5Ϯ3.5%, the mean diastolic LAD flow by 48.4Ϯ7.2%, and endocardial viability ratio (EVR) by 31.6Ϯ3.8% (PϽ0.0001). In the same animals, IABP assist increased MADP by 19.8Ϯ2.3%, mean diastolic LAD flow by 37.2Ϯ3.9%, and EVR by 21.4Ϯ3.0% (PϽ0.0001). Under acute heart failure conditions, both SMV and IABP assist significantly increased MADP, mean diastolic LAD flow, and EVR. Conclusions-In both the normal and failing circulations, the SMV was an effective counterpulsator, providing cardiac assist that was at least equal to that available from an IABP. The SMV may therefore provide the proven benefits of an IABP in ambulant patients.

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Section: Indices Of the Effectiveness Of Counterpulsationmentioning

confidence: 99%

“…6 SMVs provide category 2 assist, and the hemodynamic performance of several configurations has been demonstrated. 5,[7][8][9][10] Previous SMV models have used linings made from synthetic materials, autologous pericardium, 11 or aortic homograft. 12 The current model includes a lining made from pulmonary artery homograft.…”

Section: Smv Designmentioning

confidence: 99%

Counterpulsation From the Skeletal Muscle Ventricle and the Intraaortic Balloon Pump in the Normal and Failing Circulations

et al. 2006

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“…Small experimental SMVs with a cavity of 25 mL with less wall stress (Laplace's law), without power-increasing drug support, and without a pumping chamber were able to work up to 4 years, 12 but it is still to be proved whether these types of sack ventricles 7,11,12 will work in larger sizes of Ϸ100 to 200 mL without any drug support.…”

Section: Pumping Chambermentioning

confidence: 99%

“…They pumped for up to 4 years in the circulation. [5][6][7][8][9][10][11][12] These SMVs (sack ventricles) in dogs pumped with low stroke work because of their small chamber volume of 25 mL. To simulate a stroke volume of Ͼ1 L/min, larger SMVs had to be built.…”

mentioning

confidence: 99%

Biomechanical Hearts

et al. 2001

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Background-As shown previously in goats, clenbuterol increased the power of electrically conditioned skeletal muscle ventricles (SMVs) of clinically relevant size (150 mL), which were constructed around a mock system. They pumped against a pressure of 60 to 70 mm Hg immediately during surgery and up to several months after, finally at Ͼ1 L/min. SMVs without clenbuterol administration failed. Thus, we expected that clenbuterol-supported SMVs might become integrated into the circulation by a 1-step operation instead of the 2-step procedure required up to now. Methods and Results-In adult Boer goats (nϭ5), latissimus dorsi muscle was wrapped around a polyurethane chamber of 150 mL that was connected to the descending aorta. This muscular flow-through pumping chamber containing a stabilizing inner layer (called a biomechanical heart [BMH]) was formed and immediately made to work against a systemic load with the support of clenbuterol (5ϫ150 g/wk). During surgery, the mean stroke volume of BMHs was 53.8Ϯ22.4 mL. One month after surgery, in peripheral arterial pressure, the mean diastolic (P MD ) and minimal diastolic (P min ) pressures of BMH-supported heart cycles differed significantly from unsupported ones (P MD ϭϩ2.9Ϯ1.1 mm Hg [PϽ0.04], P min ϭϪ2.4Ϯ0.9 mm Hg [PϽ0.04]). After BMH-supported heart contractions, the subsequent maximal rate of pressure generation, dP/dt max , increased by 20.5Ϯ8.1% (PϽ0.02). One BMH, catheterized 132 days after surgery, shifted a volume of 34.

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“…SMVs and BMHs basically have two main limitations: firstly muscle damage after electrical muscle fiber transformation from a fast twitched into a slow twitched non-fatigue muscle and secondly thromboembolic complications from the blood contacting surface especially when a muscular blood pump works on demand. Former investigators developed sack-ventricles within circulation in dogs pumping up to 4 years [1][2][3][4][5]. …”

Section: Introductionmentioning

confidence: 99%