Search

Noninvasive measurements of blood pressure (BP) and cardiac output (CO) are crucial in the follow‐up of continuous‐flow left ventricular assist device (CF‐LVAD) patients. For our pilot study, we sought to compare BP measurements between a tonometry blood pressure pulse analyzer (BPPA) (DMP‐Life, DAEYOMEDI Co., Ltd., Gyeonggi‐do, South Korea) and Doppler ultrasound in CF‐LVAD patients, as well as to compare the BPPA estimated CO to LVAD calculated blood flow and to the patient's intrinsic CO estimated with transthoracic echocardiography (TTE). Ambulatory CF‐LVAD patients (6 HeartMate, 26 HeartMate II), were included. According to TTE findings, patients were then subdivided in two groups: patients with an opening aortic valve (OAV) [n = 21] and those with an intermittent opening aortic valve (IOAV) [n = 11]. We found a very good correlation of systolic BP (SBP) measurements between the two methods, BPPA and Doppler ultrasound (r = 0.87, P < 0.0001). Bland‐Altman plots for SBP revealed a low bias of −4.6 mm Hg and SD of ±4.7 mm Hg. In CF‐LVAD patients with IOAV, the BPPA‐CO had a good correlation with the LVAD‐flow (r = 0.78, P < 0.0001), but in OAV patients, there was no correlation. After adding the patient's intrinsic CO, estimated from TTE in patients with OAV to the LVAD‐flow, we found a very good correlation between the BPPA‐CO and LVAD‐flow + TTE‐CO (r = 0.81, P = 0.002). Our study demonstrated that compared with the standard clinical method, Doppler ultrasound, the BPPA measured BP noninvasively with good accuracy and precision of agreement. In addition, tonometry BPPA provided further valuable information regarding the CF‐LVAD patient's intrinsic CO. [ABSTRACT FROM AUTHOR]

Long-Term Cardiac Neurostimulation. Introduction: The right inferior ganglionated plexus (RIGP) selectively innervates the atrioventricular node. Temporary electrical stimulation of this plexus reduces the ventricular rate during atrial fibrillation (AF). We sought to assess the feasibility of chronic parasympathetic stimulation for ventricular rate control during AF with a nonthoracotomy intracardiac neurostimulation approach. Methods and Results: In 9 mongrel dogs, the small endocardial area inside the right atrium, which overlies the RIGP, was identified by 20 Hz stimulation over a guiding catheter with integrated electrodes. Once identified, an active-fixation lead was implanted. The lead was connected to a subcutaneous neurostimulator. An additional dual-chamber pacemaker was implanted for AF induction by rapid atrial pacing and ventricular rate monitoring. Continuous neurostimulation was delivered for 1–2 years to decrease the ventricular rate during AF to a range of 100–140 bpm. Implantation of a neurostimulation lead was achieved within 37 ± 12 min. The latency of the negative dromotropic response after on/offset or modulation of neurostimulation was <1 s. Continuous neurostimulation was effective and well tolerated during a 1–2 year follow-up with a stimulation voltage <5 V. The neurostimulation effect displayed a chronaxie-rheobase behavior (chronaxie time of 0.07 ± 0.02 ms for a 50% decrease of the ventricular rate during AF). Conclusion: Chronic parasympathetic stimulation can be achieved via a cardiac neurostimulator. The approach is safe, effective, and well tolerated in the long term. The atrioventricular nodal selectivity and the opportunity to adjust the negative dromotropic effect within seconds may represent an advantage over pharmacological rate control. (J Cardiovasc Electrophysiol, Vol. 21, pp. 193-199, February 2010) [ABSTRACT FROM AUTHOR]

Objective: Stented biological prostheses show different performance related to their design and ultrastructure. Therefore, we compared the Carpentier-Edwards Perimount (Edwards Lifesciences, Irvine, CA, USA) and the St. Jude Medical Epic (SJM Epic; St. Jude Medical Inc., St. Paul, MN, USA) prostheses with respect to their hemodynamic features., Methods: Eighty-six patients underwent aortic valve replacement for severe aortic stenosis (50 patients), aortic regurgitation (seven patients), or mixed lesion (29 patients) with these randomly assigned bioprostheses (Perimount: 39 patients; SJM Epic: 47 patients). Following informed consent, patients were examined postoperatively (mean 9.7 +/- 4 months after surgery) with a detailed echocardiographic study, quality of life was determined by a standardized questionnaire., Results: Comparing the indexed effective orifice area (0.77 cm(2)/m(2) vs. 0.64 cm(2)/m(2); p = 0.019), the mean pressure gradient (11.15 mmHg vs. 14.80 mmHg; p = 0.004) and the stroke-work loss (6.95% vs. 8.49%; p = 0.025), the Carpentier-Edwards Perimount demonstrated significantly better hemodynamic features than the SJM Epic prosthesis. These effects were more pronounced in the smaller prosthetic sizes., Conclusion: The Carpentier-Edwards Perimount prosthesis was less obstructive than the SJM Epic in echocardiographic controls. Patient-prosthesis mismatch as determined by indexed effective orifice area showed no impact on functional recovery.