RT Journal Article
SR Electronic
T1 Cardiac bioimpedance during exercise testing in patients with idiopathic pulmonary arterial hypertension
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP p1539
VO 38
IS Suppl 55
A1 Ralf Kaiser
A1 Christian Frantz
A1 Kerstin Hadasch
A1 Christian Lensch
A1 Robert Bals
A1 Heinrike Wilkens
YR 2011
UL http://erj.ersjournals.com/content/38/Suppl_55/p1539.abstract
AB Purpose: In idiopathic pulmonary arterial hypertension (IPAH) right ventricular insufficiency develops due to pressure overload. Furthermore left ventricular function is reduced by chronic underfilling.Hemodynamics are monitored by echocardiography and cardiac catheterisation. This may describe cardiac function only insufficient, as hemodynamics may change during exercise and balance between right and left ventricular function might change due to development of a septal shift.Methods: Spiroergometry testing was performed in 20 healthy volunteers and 21 patients with IPAH. Cardiac performance was determined using a cardiac bioimpedance instrument.Results: Patients with IPAH tolerated less workload (54.3±37 vs. 177.4±90W). Ejection fraction (EF) at baseline was comparable to control. During exercise the increase of EF was diminished in IPAH (62.1±8 vs. 67.4±5%) and maximal cardiac index (CI) was significantly lower (5.2±2 vs. 9.0±3,7l/min/qm). Enddiastolic volume (EDI) showed a trend to decreased values (102.9±41 vs. 128.8±53ml/qm), while stroke index was markedly reduced (53.5±17 vs. 72.0±21ml/qm). Peakflow during ejection was decreased (387.7±126 vs. 559.0±180ml/min/qm) as well as flow acceleration (ACI, 153.5±61 vs. 217.1±71/sec2).Conclusions: In patients with IPAH, stroke volume and CI were reduced. The diminished filling is represented by reduced EDI, resulting in less increase of contractility as shown by reduced peak flow and ACI. Patients with IPAH were not able to compensate the lack of contractility by heart rate, resulting in lower CI. Left ventricular underfilling affects cardiac performance during exercise, and inotropic response is reduced in patients with IPAH.