Size and function of the human left and right ventricles during growth

Abstract

Volume parameters of 63 left (LV) and 50 right ventricles (RV) were calculated from bi-plane angiocardiograms of infants, children and adolescents. Seventeen of the LV were from patients who were normal or had only minor abnormalities, 26 were from patients with atrial septal defect and left-to-right shunt less than 170% and 20 were from patients with pulmonary stenosis and pressure gradients less than 50 mmHg. Sixteen of the RV were from patients who were normal, 6 from patients with slight aortic regurgitation, 17 from patients with aortic stenosis or coarctation and pressure gradients less than 30 mmHg and 11 from patients with patent ductus arteriosus and left-to-right shunt less than 60%. The ejection fraction (EF) of RV [0.626 +/- 0.050 (SD)] was smaller than that of LV (0.711 +/- 0.064). There was no significant correlation (p greater than 0.05) with body surface area (BSA) (LV: r = -0.055; RV: r = -0.063) or heart rate (HR) at rest (LV: r = 0.197; RV: r = 0.179). However, EF correlated significantly with the endsystolic volume (ESV) (normalized for BSA1.22) (LV: r = -0.82; RV: r = -0.72), but not with the normalized enddiastolic volume (EDV) (LV: r = -0.05; RV: r = -0.22). For LV as well as RV, EDV and ESV, stroke volume and LV mass were proportional to BSA1.22. In contrast, the cardiac output, being the same for RV and LV, increased in proportion to BSA. There was, however, a significant correlation (r = 0.465; p less than 0.001) between cardiac index (CI) and HR at rest. At 100 beats/min CI was 4.57 +/- 0.88 litre/min/m2. The evaluation of the spatial position of LV and RV yielded a significant descent (about 18 degrees) of both ventricular apices relative to their respective semilunar valves during the period of growth. In patients with atrial septal defect (mean shunt 86%), the apex of the normal LV was shifted posteriorly by 20 degrees. These data may contribute to our understanding of the physiology of normal circulation and heart function during the period of growth.

Left ventricular muscle volume in children and young adults

“…As reported for the left and right ventricular volumes [14,17], the relationship between muscle mass and BSA was well fitted using a power function with a mean exponent of 1.22. Mass was therefore normalized for BSA Izz as were enddiastolic and end-systolic volumes (Table 2).…”

“…LV volumes at end-diastole and end-systole were calculated using the area-length method and corrected using factors appropriate for position and cardiac phase [14,17]. The conventionally selected [7,23] outer segment of the myocardial wall was approximated by three landmarks "2", "3", and "4" (Fig.…”

“…For both variables the relationship was well fitted by power functions with similar exponents, larger than 1 [14,17]. Therefore, the often used expression mass/BSA should not be used when results from infants and children are compared.…”

Normal biventricular function, volumes, and mass in children aged 8 to 17 years

“…Several groups have studied the correlation of vascular or ventricular size with BSA or functions of BSA (22)(23)(24). Recently, Sluysmans and Colan (22) demonstrated that indexing dimensions of vascular structures for BSA does not adequately account for the dependence of vascular size on BSA.…”

Angiocardiographic Pressure Volume Loops in the Analysis of Right Ventricular Function after Repair of Tetralogy of Fallot

“…Only beats recorded during expiration were analysed. We derived the following parameters from the pressure volume loops and the corresponding volume time curves in analogy to a study of Redington and colleagues: [2] (a) Right ventricular volumes: The volumes were taken from the volume time curve and corrected for the corresponding body surface area with an exponent appropriate for end diastolic and end systolic volumes since ventricular volumes increase in an over proportional manner with respect to body surface area [9]. Right ventricular end diastolic volume (RVEDV) was taken as the maximum value and end systolic volume (RVESV) was taken as the minimum value of the volume time curve.…”