Pulsus alternans induced by inferior vena caval occlusion in man

Abstract

To assess the effect of rapid preload reduction on left ventricular performance in nonischemic cardiomyopathy, 11 patients were studied during inferior vena caval (IVC) balloon occlusion. Five developed sustained pulsus alternans. During pulsus alternans, the strong beats demonstrated systolic performance characteristics similar to baseline values, despite a drop in both left ventricular (LV) end-diastolic diameter (66 +/- 13 to 61 +/- 13 mm; p less than 0.05) and LV end-diastolic pressure (21 +/- 8 to 9 +/- 6 mmHg; p less than 0.05). In contrast, the weak beats demonstrated a reduction in peak systolic pressure (130 +/- 36 to 109 +/- 33 mmHg; p less than 0.02), fractional shortening (20% +/- 4% to 17% +/- 9%; p less than 0.05) and peak positive dP/dt (1,006 +/- 224 to 921 +/- 287 mmHg; p less than 0.05). Measures of diastolic performance (peak negative dP/dt, the time constant of LV relaxation, the length of diastasis, and LV end-diastolic stress) were not different between baseline beats and the strong beats; and only LV end-diastolic stress differed when baseline beats were compared to the weak beats. When the strong beats were compared to the weak beats during induced pulsus alternans, significant differences were observed in peak systolic pressure, peak positive dP/dt, and fractional shortening, but no differences in any measured diastolic parameter was observed. A slight difference was noted in the left ventricular end-diastolic diameters, with the weak beat consistently beginning at a slightly smaller diameter (61 +/- 13; mm vs 59 +/- 13; p less than 0.05). In summary, these data are consistent with an augmentation and deletion of intrinsic contractile forces in association with an alternation in preload on a beat-to-beat basis as best describing left ventricular performance during pulsus alternans.

Attenuation of hypertensive‐induced pulsus alternans by nifedipine and nitroglycerin

“…Several studies suggest that alteration in left ventricular end diastolic volume causes the beat to beat changes observed in the left ventricular systolic pressure [ 16-1 81, while other studies support alternating contractility [ 19-241. It has also been postulated that augmentation and deletion of intrinsic contractile forces in association with an alternation in preload on a beat to beat interval best describes left ventricular performance during pulsus alternans [8,25].…”

Interpretation of cardiac pathophysiology from pressure waveform analysis: Pulsus alternans

“…The theory of pressure generation and alternation of contractility on the beat-to-beat basis with unimpaired diastolic parameters was reported by Bashore et al [7]. Pulsus alternans was induced by preload reduction with balloon occlusion of the inferior vena cava, performed during measurements of left ventricular function.…”

“…Another postulated mechanism for the alternations in pulse pressure evolved from Frank Starling's mechanism due to alterations in diastolic volume [5,16]. However, measured diastolic volumes in patient studies [7] suggest the earlier mechanism may play a predominant role. A 62-yr-old patient with congestive failure underwent cardiac catheterization for mitral regurgitation and continuing left ventricular dysfunction.…”

“…Pulsus alternans may also be transiently induced by premature ventricular contractions [4], orthostatic factors [ 5 ] , rapid atrial pacing [6], inferior vena caval occlusion [7], as well as myocardial ischemia [8]. Intracoronary contrast injection during angiography in a patient with hypertensive cardiomyopathy has also been reported to attenuate pulsus alternans [9].…”

Veränderte Interaktion von Blutdruck und Herzfrequenz bei idiopathischer dilatativer Kardiomyopathie. Pattern Analysis of Blood Pressure and Heart Rate in Idiopathic Dilated Cardiomyopathy

“…Tabelle 2 erschließt sich durch Betrachtung der diagonalen Zellenreihen. So erfaßt eine von links oben nach rechts unten gedachte Diagonale durch die Matrix in Tabelle [10,11] zurückzuführen. Bei Herzinsuffizienz wurde auch ein primär auftretender Alternans der sympathischen Innervation beschrieben [12].…”