Effect of beta blockade on exercise response after cardiac transplantation.

Bexton, R. S.; Milne, John; Cory-Pearce, R.; English, T. A. H.; Aj, Camm

doi:10.1136/hrt.49.6.584

Cited by 50 publications

(12 citation statements)

References 21 publications

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“…4 and 5). Such a gradual increase in HR was also observed during the later period of exercise in cardiac denervated dogs and heart transplant recipients, which was blunted by ␤-adrenergic blockade (3,39). Taken together, the excess development of tachycardia during the later period of exercise seems to be mediated by a humoral factor such as circulating plasma epinephrine and/or a progressive withdrawal of cardiac parasympathetic nerve activity.…”

Section: Discussionmentioning

confidence: 71%

Direct measurement of cardiac sympathetic efferent nerve activity during dynamic exercise

Tsuchimochi

Matsukawa

Komine

et al. 2002

American Journal of Physiology-Heart and Circulatory Physiology

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The assumption that tachycardia during light to moderate exercise was predominantly controlled by withdrawal of cardiac parasympathetic nerve activity but not by augmentation of cardiac sympathetic nerve activity (CSNA) was challenged by measuring CSNA during treadmill exercise (speed, 10–60 m/min) for 1 min in five conscious cats. As soon as exercise started, CSNA and heart rate (HR) increased and mean arterial pressure (MAP) decreased; their time courses at the initial 12-s period of exercise were irrespective of the running speed. CSNA increased 168–297% at 7.1 ± 0.4 s from the exercise onset, and MAP decreased 8–13 mmHg at 6.0 ± 0.3 s, preceding the increase of 40–53 beats/min in HR at 10.5 ± 0.4 s. CSNA remained elevated during the later period of exercise, whereas HR and MAP gradually increased until the end of exercise. After the cessation of exercise, CSNA returned quickly to the control, whereas HR was slowly restored. In conclusion, cardiac sympathetic outflow augments at the onset of and during dynamic exercise even though the exercise intensity is low to moderate, which may contribute to acceleration of cardiac pacemaker rhythm.

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Section: Discussionmentioning

confidence: 71%

Direct measurement of cardiac sympathetic efferent nerve activity during dynamic exercise

Tsuchimochi

Matsukawa

Komine

et al. 2002

American Journal of Physiology-Heart and Circulatory Physiology

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“…The mean length of survival after transplantation was 11 (range [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] months and all patients were receiving standard immunosuppressive treatment (prednisolone, azathioprine, and cyclosporin). In all cases a recent cardiac biopsy specimen had shown no evidence of rejection.…”

Section: Methodsmentioning

confidence: 99%

Isometric exercise in the denervated heart: a Doppler echocardiographic study.

Robson

Furniss

Heads

et al. 1989

Heart

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SUMMARY The haemodynamic responses to isometric exercise of eight recipients of orthotopic heart transplants and eight healthy controls were studied. Each performed sustained exercise at 30% of maximal voluntary contraction for three minutes on a handgrip dynamometer. Cardiac output was measured by combined Doppler and cross sectional echocardiography before exercise and every 30 seconds during and after exercise. In the controls cardiac output and blood pressure increased significantly owing to an increase in heart rate with no change in stroke volume. In the transplant group cardiac output, heart rate, and stroke volume remained unchanged throughout exercise.In contrast with its response to dynamic exercise the denervated human heart is unable to increase cardiac output during isometric exercise. The pressor response that occurs is mediated via an increase in peripheral vascular resistance.Although reinnervation of the transplanted heart has been well documented after orthotopic transplantation of the canine heart,' the transplanted human heart seems to remain both functionally and anatomically denervated indefinitely.2 Studies in normally innervated human hearts have shown that isometric exercise results in significant increases in cardiac output, heart rate, and mean blood pressure without changes in stroke volume, ventricular dimensions, or myocardial contractility." Although the transplanted denervated heart is able to maintain a relatively normal cardiac output during dynamic exercise' through the Frank-Starling mechanism, it is difficult to envisage how it can produce an appropriate increase in cardiac output during semisupine static exercise.Cardiac output can be calculated from blood velocity in the ascending aorta, measured by Doppler ultrasound, combined with aortic orifice area, measured by cross sectional echocardiography.9"0 The technique is reproducible" 12 and allows quick, non-invasive measurements of cardiac output both at rest and during supine and upright exercise."'5 Left ventricular size and performance can be accuratelyRequests for reprints to Dr S S Furniss, Regional Cardiothoracic Centre, Freeman Hospital, Newcastle upon Tyne NE7 7DN.Accepted for publication 29 November 1988 measured by M mode echocardiography.'6 '7 We used these techniques to investigate the haemodynamic changes during handgrip isometric exercise in recipients of orthotopic heart transplants and in controls. Patients and methodsEight recipients of orthotopic heart transplants (six men) were recruited. The details of the group were as follows: mean (SD) age 40 (10) years, mean (SD) height 1-71 (0-08) m, mean (SD) weight 64-8 (9.5) kg.All patients were clinically and functionally well with no clinically significant biochemical or haematological abnormality at the time of the study.Mean haemoglobin was 12 3 g/l and mean creatinine clearance was 58 ml/min. The mean length of survival after transplantation was 11 (range 5-21) months and all patients were receiving standard immunosuppressive treatment (prednisolone, azath...

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“…Aus diesem Grund kann die Applikation von -Blockern, z.B. Propranolol, den belastungsinduzierten Anstieg der Herzfrequenz blockieren und dadurch die Belastungsfähigkeit des Patienten beeinträchtigen [3]. Die Wahl der Dosis sollte deshalb die Herzfrequenz nicht < 90 Schläge/min reduzieren.…”

Section: Transplantatfunktion Während Belastungunclassified

Sport nach Herztransplantation

Kamler

Herold

Aleksić

et al. 2004

Herz

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Heart transplantation has the potential to change a patient with a life-threatening illness into an active healthy person with a potentially excellent quality of life. Survival with excellent allograft function for 10 years is now common for the majority of patients. However, exercise performance remains impaired when compared to healthy subjects. Reasons include a decrease of maximal heart rate, cardiac output and oxygen uptake, which are present after heart transplantation. The role of these abnormalities may differ as a function of time after surgery. Possible reasons like cardiac denervation, diastolic dysfunction, and endothelial dysfunction are discussed in this article. Furthermore, exercise capacity may be diminished because of peripheral limitations associated with physical deconditioning, abnormal muscle structure and function or pharmacological side effects. Endurance and strength training may greatly improve muscle function and maximal aerobic performance as well as reduce side effects of immunosuppressive therapy. Exercise should be considered a valuable tool in the long-term treatment after heart transplantation.

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Effect of beta blockade on exercise response after cardiac transplantation.

Cited by 50 publications

References 21 publications

Direct measurement of cardiac sympathetic efferent nerve activity during dynamic exercise

Direct measurement of cardiac sympathetic efferent nerve activity during dynamic exercise

Isometric exercise in the denervated heart: a Doppler echocardiographic study.

Sport nach Herztransplantation

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