Right ventricular diastolic pressure-volume relations and regional dimensions during acute alterations in loading conditions.

Abstract

Acute pharmacologically mediated parallel shifts in the left ventricular diastolic pressure-volume relation may be due to the restraining effect of the pericardium and/or leftward displacement of the interventricular septum. The existence and cause of this phenomenon in the right ventricle has not been studied in animals or in man. Accordingly, we altered right ventricular pressure with intravenous phenylephrine (0.2 to 0.3 mg) and nitroprusside (0.5 to 1.5 ,g/kg/min) to achieve three disparate peak right ventricular pressures in nine normal subjects after partial autonomic blockade with atropine (1 mg) and propranolol (0.15 mg/kg). Simultaneous high-fidelity right ventricular pressures and biplane cineventriculographic volumes were acquired during the three resultant loading conditions. Right atrial pacing maintained heart rate constant at each pressure level.

Right ventricular dysfunction during coronary artery occlusion: pressure-volume analysis using conductance catheters during coronary angioplasty

“…Right ventricular diastolic dilatation may be mechanically constrained by the pericardium, or by movement of the interventricular septum into the right ventricular cavity during left ventricular dilatation; the latter effect may explain failure of right ventricular dilatation during left anterior descending coronary artery occlusion, since acute ischaemic left ventricular dilatation would be anticipated. The patterns of change observed in the diastolic right ventricular pressure–volume relations (fig 3) support this explanation: an increase in the gradient of the diastolic pressure–volume relation implies an increase in ventricular stiffness, but a parallel upward shift of the relation is a feature of mechanical constraint of the ventricle, for example during acute volume loading of the right ventricle,21 or during acute ischaemia of the left ventricle 15. A predominantly parallel shift was a common observation during occlusion of the left anterior descending coronary artery.…”

Guidelines for the Echocardiographic Assessment of the Right Heart in Adults: A Report from the American Society of Echocardiography

“…Em função das suas paredes muito finas, o VD é extremamente sensível a elevações da pós carga (estresse de parede), especialmente na presença de doenças que afetem o miocárdio do VD, como isquemia e infarto do miocárdio. 144,152,153 O VD também é sensível a mudanças na pré-carga; uma redução na pré-carga causa uma diminuição na onda E com uma diminuição relativamente menor da onda A, e consequentemente diminuição na relação E/A. [154][155][156] O Doppler tecidual é menos dependente de carga; uma redução na pré-carga produz uma diminuição equivalente da E' e da A' e consequentemente a relação E'/A' permanece inalterada.…”

Operative contractility: A functional concept of the inotropic state

“…Preliminary data from human studies in the literature measuring right ventricular volumes with angiography or radionuclides show adequate assessment of contractility by OperCon under experimental conditions involving changes in the inotropic state 137,138 or haemodynamic loads. 139 In conclusion, we have described a model by which ventricular contractility may be readily assessed from the interaction of SV, PL and AL. The resulting operative contractility index (OperCon) was shown to be sensitive to changes in the inotropic state and little affected by haemodynamic loads.…”