The relationship between longitudinal, lateral, and septal contribution to stroke volume in patients with pulmonary regurgitation and healthy volunteers

Abstract

Septal systolic motion is towards the left ventricle (LV) in healthy hearts. Patients with pulmonary regurgitation (PR) and right ventricular (RV) volume overload have systolic septal motion toward the RV. This may affect the longitudinal contribution from atrioventricular plane displacement (AVPD) and septal and lateral contribution to stroke volume (SV). The study aimed to quantify these contributions to SV in patients with PR. Cardiac magnetic resonance imaging was used for assessment of cardiac volumes. Patients (n = 30; age 9-59 yr) with PR due to surgically corrected tetralogy of Fallot and 54 healthy controls (age 10-66 yr) were studied. Longitudinal contribution to RVSV was 47 ± 2% (means ± SE) in patients with PR and 79 ± 1% in controls (P < 0.001). Lateral contribution to RVSV and LVSV was 40 ± 1 and 62 ± 2% in patients and 31 ± 1 and 36 ± 1% in controls (P < 0.001 for both). Septal motion contributed to RVSV by 8 ± 1% in patients and by 7 ± 1% to LVSV in controls (P < 0.001). PR patients have decreased longitudinal contribution to RVSV and increased lateral pumping, resulting in larger outer volume changes and septal motion towards the RV. The changes in RV pumping physiology may be explained by RV remodeling resulting in lower systolic inflow of blood into the right atrium in relation to SV. This avoids the development of pendulum volume between the caval veins and right atrium, which would occur in PR patients if longitudinal contribution to SV was preserved. Decreased AVPD suggests that tricuspid annular excursion, a marker of RV function, is less valid in these patients.

Hydraulic forces contribute to left ventricular diastolic filling

“…The LV epicardial volume change over the cardiac cycle has been shown to be on average 25% by volume42. Moreover, the healthy LV has been shown to reduce the septal portion of the LV epicardial dimensions during the cardiac cycle, contributing to approximately 5% of LV stroke volume43. Taken together, the change in epicardial VSA during the cardiac cycle found in the current study is of a relatively small magnitude, but consistent with previous findings.…”

Effects of milrinone and epinephrine or dopamine on biventricular function and hemodynamics in right heart failure after pulmonary regurgitation

“…Following 11 wk of PR, the classical features of right heart failure secondary to volume overload were pronounced, with right ventricular dilatation (4 -6, 10, 19, 20, 24, 27), decreased RV contractility (20), reduced compliance (2)(3)(4)20), a leftward septal shift in the diastolic phase, and compromised LV pressure generation (1,19). The degree of change in RV EDVI and LV EDVI was close to what have been described as the difference in healthy adults and patients with repaired tetralogy of Fallot (28). Previous studies have mainly focused on the surgical or catheter-based treatment options, particularly valve replacement to correct the underlying cause (10,19,27).…”

“…RV physiology is particularly challenging, as the complex ventricular interaction with the LV has a major impact on preload, pressure generation, and flow in the RV (8,11,21,28). The majority of experimental studies have focused solely on RV function using models of acute or chronic pressure overload, as in pulmonary arterial hypertension, ARDS, or following banding of the pulmonary artery, for example.…”

Longitudinal left ventricular function is globally depressed within a week of STEMI

“…Atrioventricular plane displacement is the main contributor to LV SV, counting for 60% in the normal heart (Stephensen et al, 2014). Reduced AVPD has been associated with ageing (Steding-Ehrenborg et al, 2015) and disease (Stephensen et al, 2014), while increased AVPD is seen in male athletes (Steding-Ehrenborg et al, 2013). It is known that MI causes decreased AVPD (Brand et al, 2002) but it is not known how it correlates with MI size and MI location.…”