Early post-stress decrease in cardiac performance by impedance cardiography and its relationship to the severity and extent of ischemia by myocardial perfusion imaging

Abstract

Background While single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is a well-established noninvasive procedure for the evaluation of patients with coronary artery disease (CAD), it is unable to detect the presence of, or underestimates the extent of CAD in certain patients. We aimed to show that a bio-impedance device can detect early post-stress changes in several hemodynamic parameters, thereby serving as a potential marker for the presence of significant ischemia. Methods Prospectively enrolled patients, referred to our Medical Center for clinically-indicated MPI, underwent testing using a Non-Invasive Cardiac System (NICaS) before and immediately after exercise. The differences between rest and stress hemodynamic parameters were compared with the severity and extent of myocardial ischemia by MPI. The study included 198 patients; mean age was 62 years, 26% were women, 54% had hypertension, and 29% diabetes mellitus. Of them, 188 patients had ≤10%, and 10 had > 10% of myocardial ischemia. Results In the first group, there was a significantly greater increase in post-exercise stroke index, stroke work index, cardiac index and cardiac power index (19.2, 29.1, 90.5 and 107%, respectively) compared with the second group (− 2.7, 3.8, 43.7 and 53.5%, respectively), as well as a significantly greater decrease in total peripheral resistance index (− 38.7% compared with − 16.3%), with corresponding p values of 0.015, 0.017, 0.040, 0.016, and < 0.001, respectively. Conclusions Our data suggest that immediate post-stress changes in several hemodynamic parameters, detected by the NICaS, can be used as an important adjunct to SPECT MPI for the early detection of myocardial ischemia.

Cardiopulmonary exercise testing and impedance cardiography in the assessment of exercise capacity of patients with coronary artery disease early after myocardial revascularization

“…A clinically relevant aspect of myocardial ischemia is indicated by significant correlations between absolute SV values and O2 pulse at AT and at peak exercise. Goldkorn et al demonstrated the correlation of early postexercise SV reduction with a extent of ischemia above 10% in myocardial perfusion imaging [ 29 ]. The abnormal SV reduction in response to exercise observed in the evaluated CAD patients post coronary revascularization, confirms Chaudhry’s [ 7 ] hypothesis of a significant association between peak VO 2 and both microcirculatory function and peripheral factors.…”

No improvement of physical capacity during cardiac rehabilitation in a patient with elevated IGF-1 and normal pressure hydrocephalus

“…Czułość EKG wysiłkowego w diagnostyce choroby wieńcowej szacuje się jednak na 68%, a swoistość na 77% [6]. Za chorobą niedokrwienną przemawiały granicznie niskie bezwzględne wartości O 2 Pulse i redukcja wartości SV w trakcie wysiłku po osiągnięciu AT [4,[7][8][9]. Niezdolność do utrzymania odpowiedniej do wysiłku SV po AT wraz z nieprawidłową reakcją w zakresie oporu obwodowego (ang.…”