Impedance cardiography: a useful and reliable tool in optimization of cardiac resynchronization devices

Aims Optimizing cardiac resynchronization therapy (CRT) devices has become more complex since modification of both atrioventricular (AV) and interventricular (VV) stimulation intervals has become possible. The current paper presents data from the routine use of impedance cardiography (IC)-based cardiac output (CO) measurements to guide the optimization of AV-and VV-interval timing of CRT devices. Methods and results Forty-six patients with heart failure (left ventricular ejection fraction ,35%, New York Heart Asociation (NYHA) III-IV) and left bundle branch block (.130 ms) in sinus rhythm were evaluated 3-5 days after implantation of a CRT device by means of IC. CO was measured without pacing and with biventricular pacing using a standard protocol of VV-and AV-interval modification from 260 to þ60 ms and 80 to 140 ms, respectively, in 20 ms steps. Mean CO without pacing was 3.66 + 0.85 L/min and significantly increased to 4.40 + 1.1 L/min (P , 0.05) with simultaneous biventricular pacing and an AV interval of 120 ms. 'Optimizing' both VV and AV intervals further increased CO to 4.86 + 1.1 L/min (P , 0.05). Maximum CO was measured in most patients with left ventricular pre-excitation. The proportion of 'nonresponders' to CRT was reduced by 56% following AV-and VV-interval modification using IC guidance. Conclusion Modification of both AV and VV intervals in patients with a CRT device significantly improves CO compared with standard simultaneous biventricular pacing and no pacing. IC is a useful non-invasive technique for guiding this modification. Marked variability of optimal AV and VV intervals between patients requires optimization of these intervals for each patient individually

Interleukin-6, -7, -8 and -10 predict outcome in acute myocardial infarction complicated by cardiogenic shock

The IABP-SHOCK-trial was a morbidity-based randomized controlled trial in patients with infarction-related cardiogenic shock (CS), which used the change of the quantified degree of multiorgan failure as determined by APACHE II score over a 4-day period as primary outcome measure. The prospective hypothesis was that adding IABP therapy to "standard care" would improve CS-triggered multi organ dysfunction syndrome (MODS). The primary endpoint showed no difference between conventionally managed cardiogenic shock patients and those with IABP support. In an inflammatory marker substudy, we analysed the prognostic value of interleukin (IL)-1β, -6, -7, -8, and -10 in patients with acute myocardial infarction complicated by cardiogenic shock