Effect of Atrial Volume on the Performance of a Sac-Type Artificial Heart

Ja, Brighton; Za, Wade; Ws, Pierce; Ws, Phillips; O'Bannon, W

doi:10.1097/00002480-197301900-00100

Cited by 13 publications

(6 citation statements)

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“…Brighton et al (1) and Peters et al (4th Annual Meeting of the Biomedical Engineering Society, 1973) have observed that the addition of a flexible atrium to the inlet of an artificial heart substantially improves the heart's output. However, performance of an artificial heart is not equal to that of the natural ventricle, and doubt still exists about the physiological significance of atrial compliance.…”

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confidence: 99%

Importance of Atrial Compliance in Cardiac Performance

Suga

1974

Circulation Research

141

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Effects of changes in atrial compliance on cardiac performance were analyzed using a circulatory analog model. The atrium was assumed to be a noncontracting chamber with a constant compliance. It connected the venous return system, which was represented by mean circulatory filling pressure and a venous return resistance in accordance with Guyton's concept, with the ventricle, which was characterized by a time-varying elasticity. Atrial compliance was increased from near zero to a value at which atrial volume was twice ventricular stroke volume, while the parameters of ventricular contractility were kept unchanged. Cardiac output increased from 2,400 to 3,240 ml/min with increases in atrial compliance from 0.1 to 20 ml/mm Hg (venous return resistance 0.1 mm Hg sec/ml), whereas mean atrial pressure simultaneously decreased from 3.0 to 2.2 mm Hg. This result indicates that cardiac performance in terms of the cardiac output-mean atrial pressure relationship was markedly improved by increases in atrial compliance in spite of constant ventricular contractility. The analysis of the model strongly suggests that natural atrial compliance in situ, by pooling venous return flow during systole and supplying it to the ventricle during diastole, facilitates the transformation of the continuous venous return flow into the intermittent ventricular filling flow. KEY WORDS ventricular filling cardiac outputStarling's law of the heart atrial function circulatory analog model atrial size venous return• The physiological significance of atrial compliance is not well understood, but some indirect evidence does suggest that it is important in hemodynamics. Brighton et al. (1) Society, 1973) have observed that the addition of a flexible atrium to the inlet of an artificial heart substantially improves the heart's output. However, performance of an artificial heart is not equal to that of the natural ventricle, and doubt still exists about the physiological significance of atrial compliance.The purpose of the present analysis was to evaluate quantitatively the importance of atrial compliance in natural cardiac performance. In animal experiments, it is difficult to change atrial compliance alone without affecting venous return resistance, and slight changes in venous return resistance sensitively affect cardiac output (2). Therefore, a reasonable analog model of the cardiovascular system based on physiological findings in the literature was used in the present study. Atrial compliance was varied in the model while the other parameters of the venous return systemventricular contractile state, valve characterisFrom the Department of Physiology, Faculty of Medicine, University of Tokyo, Japan.Received January 2, 1974. Accepted for publication March 19, 1974. tics, and arterial pressure-were kept constant. The results of this analysis suggest that an atrium with an appropriate compliance can increase cardiac output 35-80%. Figure 1 shows the electric analog model of the circulatory system used in the present study; the right h...

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confidence: 99%

Importance of Atrial Compliance in Cardiac Performance

Suga

1974

Circulation Research

141

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“…In patients with preoperative suprasystemic pulmonary artery pressures, there was a statistically significant less VIS score (16 [11-23.5] vs. 18 [13][14][15][16][17][18][19][20][21][22][23][24][25], p value .044), hours of ventilation (20 [14-37] | 4567 nonsignificant less ICU stay (7 [5.5-9] vs. 7 [6][7][8][9], p value .886) in the group with a PFO with respect to the other group in which no PFO was created (Table 3, Figure 2). There was statistically significant less VIS score, hours of ventilation, inotropic support, and hospital stay in supracardiac, cardiac, and the infracardiac group (Table 4).…”

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confidence: 99%

Implications of left atrial enlargement and patent foramen ovale creation on early surgical outcomes in patients with total anomalous pulmonary venous connection

Mishra

Halder

Bansal

et al. 2021

Journal of Cardiac Surgery

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Introduction: In patients with total anomalous pulmonary venous connection (TAPVC), left atrium (LA) is small and suprasystemic pulmonary artery (PA) pressures may be present in some patients. In our study, we studied the relationship between surgical LA enlargement and patent foramen ovale (PFO) creation separately on the outcomes of patients with TAPVC.Materials and methods: Out of the 130 patients operated in our institute between January 2014 and December 2020, LA was enlarged in 60 patients. LA enlargement was done using a larger patch for atrial septal defect (ASD) closure. Thus, the LA volume was increased by shifting the patch towards the right atrium (RA). Suprasystemic or high PA pressures were present in 60 patients. In 33 patients, PFO was created. Early surgical outcomes were determined on the basis of vasoactive inotropic score (VIS), hours of ventilation, hours of inotropic support, intensive care unit (ICU) stay, and hospital stay.Result: Between the LA enlarged and nonenlarged group there was statistically significant less VIS score (18 [13-27.5] vs. 24 [18-30], p value .019), hours of ventilation (23 [16-46.5] vs. 26 [18-60], p value .039), hours of inotropic support (45.5 [30-72] vs. 55 [38-84], p value .038), and ICU stay (7 [5-9] vs. 8 [7-10] p value .0352) and statistically nonsignificant less hospital stay (11.5 [9-13] vs.12 [9-14], p value .424). In patients with preoperative suprasystemic or high PA pressures, there was a statistically significant less VIS score (16 [11-23.5] vs. 18 [13-25], p value .044), hours of ventilation (20 [14-37] vs. 22 [18-39], p value .038), hours of inotropic support (34 [29.5-71] vs. 38 [30-78], p value .042), and hospital stay (9 [5-12] vs. 11 [9-14], p value .038) and statistically nonsignificant less

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“…~' 182 W. Krautzberger et al Er besagt, dal3 bei konstant gehaltenen Antriebsparametern das SchlagSchlagvolumen des kfinstlichen Herzens abh/ingig ist yon den Drucken in den VorhSfen [7,8]. Erm5glicht wird dies durch das Prinzip des pneumatischen Antriebs und der entsprechenden Elastizit/~t der transmittierenden Membran.…”

Section: Totaler Peripherer Widerstandunclassified

“…Z. zur Verffigung stehenden kfinstliehen Ventrikeln hingewiesen und entspreehende ~derungen bzw. Fortentwieklungen der Einflul3klappen, der Herzform und auch der Aktionsform der kfinstlichen Ventrikel gefordert [13,2,8].…”

Section: Diskussionunclassified

H�modynamik nach Ersatz des Herzens durch eine inkorporierte doppelkammerige Blutpumpe

Krautzberger

Clevert

Keilbach

et al. 1974

Langenbecks Arch Chiv

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Haemodynamic after Total Heart Replacement by an Incorporated Double Chamber Blood PumpSummary. The paper reports on haemodynamic observations in 20 calves surviving total heart replacement by an incorporated double chamber blood pump for more than 10 h. The following parameters are registered:--pressures in both atria and vena cava inferior, --pressures in aorta and pulmonary artery, --pressures in both artificial ventricles, --pressures in the pneumatic driving system, --perfusion volumes and AVDO 2. It is demonstrated that the artificial blood pumps are able to obtain a perfusion volume sufficient for the animal's vitality.A sufficient regulation can be achieved by varying the driving system and by the so called Starling-mechanism of the artificial heart.In the long time surviving animals an increase of the right atrium pressure, and of the perfusion volumes is found while total peripheral resistance decreases.To explain these observations, disturbances of the neurohumoral circulatory control by the action of the artificial pumps or the development of sepsis are discussed.

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Effect of Atrial Volume on the Performance of a Sac-Type Artificial Heart

Cited by 13 publications

References 0 publications

Importance of Atrial Compliance in Cardiac Performance

Importance of Atrial Compliance in Cardiac Performance

Implications of left atrial enlargement and patent foramen ovale creation on early surgical outcomes in patients with total anomalous pulmonary venous connection

H�modynamik nach Ersatz des Herzens durch eine inkorporierte doppelkammerige Blutpumpe

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