Publications by authors named "Shanker Chandiramani"

2 Publications

  • Page 1 of 1

Programming antitachycardia pacing for primary prevention in patients with implantable cardioverter defibrillators: results from the PROVE trial.

J Cardiovasc Electrophysiol 2010 Dec;21(12):1349-54

Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, Texas, USA.

Objectives: the PROVE trial was designed to determine if antitachycardia pacing (ATP) is clinically beneficial for primary prevention in patients who have implantable cardioverter defibrillators (ICDs) or cardiac resynchronization therapy defibrillators (CRT-Ds).

Background: use of ICDs and CRT-Ds reduces mortality in patients with ventricular dysfunction and mild to moderate heart failure. However, in studies of the primary prevention population, shock-only ICDs are predominantly used, without ATP programming for less painful termination of ventricular tachycardia (VT).

Methods: we conducted a prospective, nonrandomized, multicenter study using market-released ICDs and CRT-Ds. Patients received devices programmed to deliver ATP for VT cycle lengths of 270-330 ms. Follow-up evaluation was performed at 3, 6, and 12 months. The incidence of VT and the rate of successful termination by ATP were analyzed.

Results: of 830 patients in the study population (men, 73%; mean age, 67.3 ± 12 years), 32% received single-chamber ICDs, 44% dual-chamber ICDs, and 24% CRT-Ds. ATP was attempted for 112 VT episodes in 71 patients, and 103 (92%) of the VT episodes were successfully terminated. Three VT episodes were accelerated by ATP and required termination by ICD shock; 6 episodes terminated spontaneously or by ICD shock.

Conclusions: VT is common in patients without a history of this arrhythmia who have received ICDs or CRT-Ds for primary prevention indications. Programming ICDs for ATP therapy at the time of implantation could potentially terminate most VT episodes and reduce the number of painful shocks for these patients.
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December 2010

Heart rate changes during acute mental stress with closed loop stimulation: report on two single-blinded, pacemaker studies.

Pacing Clin Electrophysiol 2007 Aug;30(8):976-84

Bluegrass Cardiology, 3 Audubon Plaza Drive, Louisville, KY 40217, USA.

Background: Mental stress affects hemodynamic properties of the heart in patients indicated for a pacemaker, therefore highlighting the need for a rate-adaptive sensor that responds to mental loads. One such sensor utilizes Closed Loop Stimulation (CLS), which translates right ventricular contractility into patient specific pacing rates. Clinical studies utilizing CLS [Emotional Response (ER) and Emotional Response 2 (ER2) studies] have been performed to confirm CLS provides appropriate heart rate response to acute mental stress. The objective of these studies was to compare heart rates during a mental stress test, with the patient's pacemaker programmed to a CLS pacing mode and an accelerometer pacing mode.

Methods: Patients were implanted with a BIOTRONIK Protos/CLS pacemaker (Berlin, Germany) and subjected to mental stress testing. The stress test consisted of a relaxation period followed by a color-word test and an arithmetic challenge test. The ER2 study utilized a randomized study design, in which pacing mode testing order was randomized.

Results: Analysis included patients who exhibited at least 80% sensor-driven heart rates during stress testing. Results for both studies demonstrated that CLS provided a statistically significant higher increase in heart rate during testing compared with an accelerometer pacing mode. The studies also showed that CLS provided a statistically significant higher peak heart rate during testing compared with an accelerometer pacing mode.

Conclusions: The ER and ER2 studies demonstrate that the CLS algorithm responds with an appropriate heart rate response to acute mental stress in patients exhibiting a high percentage of sensor-driven pacing.
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August 2007