Evaluation of heart function with impedance cardiography in acute myocardial infarction patients

To evaluate the capability of impedance cardiography (ICG) in reflecting the cardiac functions of acute myocardial infarction (AMI) patients.

99 inpatients with initial AMI were recruited. Venous blood was obtained for detection of N-terminal brain-type natriuretic peptide (NT-proBNP), B-Type natriuretic peptide (BNP) and c troponin-T (cTnT) followed by ICG. Thorax fluid capacity (TFC), pre-ejection period (PEP), left ventricular ejection fraction (LVEF), cardiac output (CO), stroke volume (SV), stroke index (SI), systemic vascular resistance (SVR), systemic vascular resistance index (SVRI), cardiac index (CI), end-diastolic volume (EDV) and systolic time ratio (STR) were measured. All these patients underwent ICG and echocardiography 2 days after surgery.

Our results indicated NT-proBNP and BNP were associated with SVR, SVRI, PEP and STR, independently (P < 0.05). cTnT was associated with SVR and SVRI (P < 0.05). And the outcomes showed correlation between ICG and echocardiography in SV, SI, EDV, LEVT, STR, LVEF (P < 0.01), CO and CI (P < 0.05). However, no correlation was noted in PEP. In addition, changes were also found in the blood pressure and heart rate 7 days after PCI.

May be ICG data could reflect the early cardiac functions of AMI patients, but the accuracy of ICG in evaluating cardiac functions should be combined with detection of blood NT-proBNP, BNP and cTnT and echocardiography.