Assessment of Myocardial Contractility by SonR Sensor in Patients Undergoing Cardiac Resynchronization Therapy.

BACKGROUND: SonR sensor signal correlates well with myocardial contractility expressed in terms of left ventricular (LV) dP/dt max. The aim of our study was to evaluate the changes in myocardial contractility during isometric effort in heart failure patients undergoing cardiac resynchronization therapy (CRT) with right atrial SonR sensor. METHODS: Thirty-one patients (19 men, 65 ± 7 years, LV ejection fraction [LVEF] 28% ± 5%, in sinus rhythm) were implanted with a CRT-defibrillator (CRT-D) device equipped with SonR sensor, which was programmed in VVI mode at 40 beats/min. Twenty-four hours after implantation, each patient underwent a noninvasive hemodynamic evaluation at rest and during isometric effort, including: (1) measurement of beat-to-beat endocavitary SonR signal; (2) echocardiographic assessment; and (3) continuous measurement of blood pressure with Nexfin method (BMEYE, Amsterdam, the Netherlands). The following contractility parameters were considered: (1) mean value of beat-to-beat SonR signal; (2) mean value of LV dP/dt by Nexfin system; and (3) fractional shortening (FS) by echocardiography. RESULTS: At the third minute of the isometric effort, mean value of SonR signal significantly increased from baseline (P < 0.001). Similarly, mean value of both LV dP/dt by Nexfin and FS significantly increased compared to the resting condition (P < 0.001; P < 0.001). While in 27 (88%) patients SonR signal increased at the third minute of the isometric effort, in four (12%) patients SonR signal decreased. In these patients, both LV dP/dt by Nexfin and FS consensually decreased. CONCLUSIONS: In CRT patients, SonR sensor is able to detect changes in myocardial contractility in a consensual way like noninvasive methods such as Nexfin system and echocardiography.

Acute insulin resistance assessed by the homeostatic model assessment in acute coronary syndromes without previously known diabetes.

We assessed the incidence and the prognostic role for early death of acute insulin resistance (by means of homeostatic model assessment [HOMA] index) in 1350 patients with acute coronary syndrome (ACS) consecutively admitted to our intensive cardiac care unit (ICCU). The incidence of HOMA positivity was 5% (68 of 1350), with the highest percentage of HOMA positivity among ST-segment elevation myocardial infarction (STEMI). Patients with HOMA positivity showed a higher body mass index (P = .003), lower values of admission and discharge left-ventricular ejection fraction (LVEF; P < .001 and P = .003, respectively), and higher levels of peak troponin I (Tn I; P < .001). The HOMA index was an independent predictor of early death (odds ratio 1.724, 95% confidence interval 1.252-2.375, P = .001). In patients with ACS and without previously known diabetes, acute insulin resistance (HOMA index) is associated with a larger myocardial damage (ie, higher values of peak Tn I and lower LVEF) and a greater inflammatory activation (indicated by correlation with leukocyte count). The HOMA positivity was an independent predictor of in-ICCU mortality.