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14.7 Autonomic nervous activity in patients with left ventricular assist devices evaluated with power spectral analysis
Cardiac TransplantZAugmentatn strength and duration of LDM activity is often controlled by varying the number of stimuli per contraction, from one to as many as five bursts. This study was intended to clarify the histopathology of the transverse, oblique, and lateral segments of the LDM after progressively greater degrees of stimulation. Methods: Three stimulation regimens (single stimulus, bursts of two stimuli, and bursts of three stimuli) were used at rates of 4.5, 70, and 100 contractions per min in muscles and their contralateral counterparts (control). The muscles were then harvested, stained, and evaluated with the aid of a computer-image analysis system. Results: As compared with the controls, all stimulated muscles lost 12-50% in weight. Additionally, all showed a decrease in fast-fiber diameter. Segmental response varied considerably with the number and area of slow and intermediate fibers, and was greatest in the oblique and lateral segments. Bursts of three stimuli minimized weight loss and resulted in higher ratios of slow and intermediate fibers. Conclusions: All stimulated muscles lost significant weight. Changes in fast-to-slow fiber ratios may be due to destruction of fast fibers. CarefuI location of biopsy sites was necessary because of large segmental variations in fast-to-slow fiber ratios of normal muscles. Stimuli in bursts of less than three seem to result in greater weight loss and less favorable fast-toslow fiber ratios in normal muscles.
14.6 Develupment of Biomechanical Hearts-Muscle Powered Blood Pumps Dynamically Trained Within Circulation N.B! GULDNER, P. KLAPPROTH, T. FISCHER and H.H. SIEVERS, Liibeck, Germany The study aim was to develop a sufficient biomechanical heart, by optimizing dynamic training of skeletal muscle ventricles (SMVs). This was achieved by wrapping the latissimus dorsi muscle around an elastic training device. In 37 adult Boer goats, dynamic training was observed up to 14 months. In group I, with 25 goats, the stimulation pattern and an increasing load were optimized for best SMV performance. The SMVs of group II (five goats), were trained as in group I with the addition of clenbuterol, a beta-2 stimulator. SMVs in group III (three goats) were trained as in group II but with high load from the beginning under stepwise increments of burst frequency. The efficient training technique in group III was then applied in group IV (four goats) to perform biomechanical hearts within the circulation consisting of dynamically trained SMVs and special designed ventricular inlays. In group I it was proved that only energy adapted dynamic training was optimal. SMVs of 150 g delivered 7 kJ per day and SMVs of 300g up to 15 kJ per day. This energy was nearly doubled by clenbuterol support in group II. The dynamic energy adapted ‘high load’ training of group III delivering up to 30 kJ per day was successfully applied in group IV Biomechanical hearts performed within the circulation in a one-stage operation and trained from the beginning were established. These biomechanical hearts with a muscle mass of 300g were pumping up to 1.0 to 1.4 per min continuously.
CARDIOVASCULAR SURGERY SEPTEtvlBER 1997
14.7 Autonomic Nervous Activity in P@ktts w&h Left Ventricular Assist Devices Erakted W&h Power Spectral Analysis T. TEDORIYA, J. SEHESTED, S. SAKAGAMI, YG. WENG and R. HETZER, Berlin, Germany We assessed the autonomic nervous activity with power spectrum analysis of heart rate variability in patients with left ventricular assist device (LVAD). Nine patients with LVAD underwent R-R interval power spectral analysis in a supine position (10min) and a 60 degree head-up tilt position (10 min). Blood pressure was continuously recorded at a finger tip with a continuous percutaneous BP monitor. All patients were stable with LVAD assist at least 1 month after surgery. All patients had no medication except anriptielet agents. ECG was continuously recorded with a Fukuda SM-26 two channel ambulatory recorder (Fukuda Denshi Co., Tokyo, Japan). Power spectral analysis of the monitoring tape was performed with a Fukuda SCM-280 Holter tape analyzer (Fokuda Denshi Co., Tokyo, Japan) and a microcomputer (PC-9801, NIX Co., Tokyo, Japan). The last 256 consecutive heart beats were processed by a fast Fourier transformation algorithm to obtain the O.Ol-l.OOHz frequency band. Then, two major spectral components could be clearly distinguished, a low frequency component (LF: 0.04-0.15 Hz) and a high frequency component (HF: 0.15-0.40Hz). The ratio of LF over HF (LF&IF) was calculated, which is generaBy considered to indicate sympathetic nerve activity. As a control study, 17 healthy young adults (mean age: 27.5 years old) underwent the same procedure as stated above. BP in the LVAD patients was 103 +/-13mmHg in a supine position, and decreased to 83+/-14 mmHg in a head-up position (P < 0.011, and did not recover at the end of the interval (10 min) of a tilt-up position. The mean value of LF/I-IF in the LVAD patients was 4.8+/-2.5 in a supine position, 6.6+/-3.8 in the position of 60 degrees. Compared with normal subjects, LF/HF in a supine position was significantly higher than the control value of 1.6+/-0.6. However there was no significant difference in the tilt position. Moreover, in LVAD patients LF/HF did not increased statistically by a tilt stress. We conclude that patients with LVAD are sympathetic dominant autonomic nervous status. However, the response to sympathetic stress was moderately inhibited.
14.8 Bloc Heart and Lung Transplantation S. MATTILA, L. HEIKKILA, J. SIPPONEN, K. VERKKALA, K. KYijSOLA, M . HALME, P. TUKIAINEN and M. S. NIEMINEN, Helsinki, Finland
En
Between June 1988 and December 1996 15 en bloc heart and lung transplantations were performed in our institution. There were nine men and six women, aged 17-61 (mean 42.3) years. The indications for operation were primary pulmonary hypertension with right heart failure in five syndroma Eisenmenger in five, puimonary embolism and right heart failure in three and emphysema pulmonum with right heart failure in two cases. The hospital (30 day) mortality was four patients (26.6%). The causes of mortality were graft failure in two cases,
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14.6 Develupment of Biomechanical Hearts-Muscle Powered Blood Pumps Dynamically Trained Within Circulation N.B! GULDNER, P. KLAPPROTH, T. FISCHER and H.H. SIEVERS, Liibeck, Germany The study aim was to develop a sufficient biomechanical heart, by optimizing dynamic training of skeletal muscle ventricles (SMVs). This was achieved by wrapping the latissimus dorsi muscle around an elastic training device. In 37 adult Boer goats, dynamic training was observed up to 14 months. In group I, with 25 goats, the stimulation pattern and an increasing load were optimized for best SMV performance. The SMVs of group II (five goats), were trained as in group I with the addition of clenbuterol, a beta-2 stimulator. SMVs in group III (three goats) were trained as in group II but with high load from the beginning under stepwise increments of burst frequency. The efficient training technique in group III was then applied in group IV (four goats) to perform biomechanical hearts within the circulation consisting of dynamically trained SMVs and special designed ventricular inlays. In group I it was proved that only energy adapted dynamic training was optimal. SMVs of 150 g delivered 7 kJ per day and SMVs of 300g up to 15 kJ per day. This energy was nearly doubled by clenbuterol support in group II. The dynamic energy adapted ‘high load’ training of group III delivering up to 30 kJ per day was successfully applied in group IV Biomechanical hearts performed within the circulation in a one-stage operation and trained from the beginning were established. These biomechanical hearts with a muscle mass of 300g were pumping up to 1.0 to 1.4 per min continuously.
CARDIOVASCULAR SURGERY SEPTEtvlBER 1997
14.7 Autonomic Nervous Activity in P@ktts w&h Left Ventricular Assist Devices Erakted W&h Power Spectral Analysis T. TEDORIYA, J. SEHESTED, S. SAKAGAMI, YG. WENG and R. HETZER, Berlin, Germany We assessed the autonomic nervous activity with power spectrum analysis of heart rate variability in patients with left ventricular assist device (LVAD). Nine patients with LVAD underwent R-R interval power spectral analysis in a supine position (10min) and a 60 degree head-up tilt position (10 min). Blood pressure was continuously recorded at a finger tip with a continuous percutaneous BP monitor. All patients were stable with LVAD assist at least 1 month after surgery. All patients had no medication except anriptielet agents. ECG was continuously recorded with a Fukuda SM-26 two channel ambulatory recorder (Fukuda Denshi Co., Tokyo, Japan). Power spectral analysis of the monitoring tape was performed with a Fukuda SCM-280 Holter tape analyzer (Fokuda Denshi Co., Tokyo, Japan) and a microcomputer (PC-9801, NIX Co., Tokyo, Japan). The last 256 consecutive heart beats were processed by a fast Fourier transformation algorithm to obtain the O.Ol-l.OOHz frequency band. Then, two major spectral components could be clearly distinguished, a low frequency component (LF: 0.04-0.15 Hz) and a high frequency component (HF: 0.15-0.40Hz). The ratio of LF over HF (LF&IF) was calculated, which is generaBy considered to indicate sympathetic nerve activity. As a control study, 17 healthy young adults (mean age: 27.5 years old) underwent the same procedure as stated above. BP in the LVAD patients was 103 +/-13mmHg in a supine position, and decreased to 83+/-14 mmHg in a head-up position (P < 0.011, and did not recover at the end of the interval (10 min) of a tilt-up position. The mean value of LF/I-IF in the LVAD patients was 4.8+/-2.5 in a supine position, 6.6+/-3.8 in the position of 60 degrees. Compared with normal subjects, LF/HF in a supine position was significantly higher than the control value of 1.6+/-0.6. However there was no significant difference in the tilt position. Moreover, in LVAD patients LF/HF did not increased statistically by a tilt stress. We conclude that patients with LVAD are sympathetic dominant autonomic nervous status. However, the response to sympathetic stress was moderately inhibited.
14.8 Bloc Heart and Lung Transplantation S. MATTILA, L. HEIKKILA, J. SIPPONEN, K. VERKKALA, K. KYijSOLA, M . HALME, P. TUKIAINEN and M. S. NIEMINEN, Helsinki, Finland
En
Between June 1988 and December 1996 15 en bloc heart and lung transplantations were performed in our institution. There were nine men and six women, aged 17-61 (mean 42.3) years. The indications for operation were primary pulmonary hypertension with right heart failure in five syndroma Eisenmenger in five, puimonary embolism and right heart failure in three and emphysema pulmonum with right heart failure in two cases. The hospital (30 day) mortality was four patients (26.6%). The causes of mortality were graft failure in two cases,
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