Frank Eberhardt

Long term complications in single and dual chamber pacing are influenced by surgical experience and patient morbidity

Objective: To determine how short and long term complication rates after pacemaker implantation are influenced by patient morbidity, operator experience, and choice of pacing system. Design: Retrospective analysis of 1884 patients who received VVI (n  =  610), VDD (n  =  371), or DDD devices (n  =  903) between 1990 and 2001. Follow up period was 64 (34) months. The influence of age, sex, coronary artery disease, myocardial infarction, reduced left ventricular (LV) function, right ventricular (RV) dilatation, atrial fibrillation, device type, and operator experience on operation time and complication rate were analysed. Results: Operation time was prolonged in patients with coronary artery disease, inferior myocardial infarction, reduced LV function, and RV dilatation. Implantation of DDD pacemakers prolonged operation time, particularly among operators with a low or medium level of experience. The overall complication rate was 4.5%. Sixty seven per cent of these complications occurred within the first three months. Complication rate was increased by age, reduced LV function, and RV dilatation. Implantation of DDD systems led to a higher complication rate (6.3%) than implantation of VVI (2.6%) or VDD pacemakers (3.2%). These differences were present only among operators with a low or medium level of experience. Conclusions: Operation time and complication rate increased with age, impaired LV function, and RV dilatation. Complication rates were higher with DDD than with VVI or VDD implantation and were excessive among inexperienced but not experienced operators.

The effect of biventricular pacing after coronary artery bypass grafting: a prospective randomized trial of different pacing modes in patients with reduced left ventricular function.

OBJECTIVES Biventricular pacing acutely improves left ventricular function in patients with heart failure and left ventricular dyssynchrony. Pressure-volume loop analysis has shown acute perioperative hemodynamic benefits of biventricular pacing immediately after weaning from cardiopulmonary bypass in patients undergoing coronary artery bypass grafting, but whether these effects can be maintained for the early postoperative period is unclear. We hypothesized that biventricular pacing is superior to atrioventricular universal pacing at right ventricular outflowtract and atrial inhibited pacing in patients undergoing coronary artery bypass grafting. METHODS Ninety-four patients (mean age, 67 +/- 9 years; mean ejection fraction, 35% +/- 4%) were prospectively randomized to undergo biventricular, atrioventricular universal, or atrial inhibited pacing at 90 beats/min for 96 postoperative hours. Clinical end points and postoperative hemodynamics, aminoterminal pro-brain natriuretic peptide, inotropic support, atrial fibrillation, ventricular arrhythmias, and renal function were evaluated. RESULTS Diastolic pulmonary arterial pressure, mean arterial pressure, mixed venous saturation, cardiac index, and cardiac power index did not differ significantly among groups for all time points. Neither raw aminoterminal pro-brain natriuretic peptide nor differential from preoperative values differed significantly among groups at any time point. Median intensive care unit stay (19.5 hours) did not differ significantly by pacing mode. Incidences of postoperative atrial fibrillation were 40% for atrial inhibited, 29% for atrioventricular universal, and 37% for biventricular (differences not significant). Renal function was unaffected by pacing mode. CONCLUSION Despite short-term hemodynamic benefits for patients with reduced left ventricular function, biventricular pacing did not lead to improved postoperative hemodynamics or clinical outcome.

The effect of biventricular pacing on cardiac function after weaning from cardiopulmonary bypass in patients with reduced left ventricular function: A pressure–volume loop analysis

OBJECTIVE Patients with severely reduced left ventricular function undergoing coronary artery bypass grafting have increased complication rates. We hypothesized that temporary postoperative atrial synchronous biventricular pacing would improve left ventricular function after cardiopulmonary bypass. METHODS A left ventricular pressure-volume catheter was placed in 21 patients undergoing coronary artery bypass grafting (ejection fraction 29% +/- 5%). Pressure-volume loops were obtained after weaning from cardiopulmonary bypass with atrial synchronous biventricular, left ventricular, and right ventricular outflow tract pacing and atrial-only stimulation at 90 beats/min. RESULTS Steady-state systolic and preload-independent parameters were superior for atrial synchronous biventricular and left ventricular pacing and atrial-only pacing relative to atrial synchronous right ventricular outflow tract pacing (P < .05). Diastolic parameters, excepting maximum negative rate of left ventricular pressure change, were unaffected. No significant differences were observed between atrial synchronous biventricular and left ventricular pacing and atrial-only pacing. Systolic dyssynchrony was significantly lower for atrial synchronous biventricular pacing (21% +/- 5%), atrial synchronous left ventricular pacing (20% +/- 6%), and atrial-only pacing (20% +/- 6%) versus atrial synchronous right ventricular outflow tract pacing (25% +/- 7%, P < .05). Atrioventricular interval during atrial-only stimulation was positively correlated with difference in stroke work between atrial synchronous biventricular pacing and atrial-only pacing (r(2) = 0.78, P > .001). CONCLUSION Postoperative atrial synchronous biventricular and left ventricular pacing and atrial-only stimulation significantly improve systolic function relative to atrial synchronous right ventricular outflow tract pacing. If atrioventricular conduction is prolonged, atrial synchronous biventricular pacing is preferable to atrial-only pacing.

Changes in Heart Rate, Heart Rate Variability, and Heart Rate Turbulence during Evolving Reperfused Myocardial Infarction

Depressed cardiac parasympathetic activity is associated with electrical instability and adverse outcomes after myocardial infarction (MI). Heart rate turbulence (HRT), reflecting reflex vagal activity, and heart rate variability (HRV), reflecting tonic autonomic variations are both reduced in the subacute phase of MI. However, the evolution of these components of cardiac autonomic control between subacute and chronic phase of MI has not been defined. We prospectively studied 100 consecutive patients with a recent first MI with ST‐segment elevation, who underwent successful direct percutaneous coronary interventions. Beta‐adrenergic blockers and angiotensin‐converting enzyme (ACE) inhibitors were administered according to the state‐of‐the‐art medical practice guidelines. HRT and HRV were measured from 24‐hour ambulatory electrocardiographic recordings 10 days and 12 months after the index MI. There was no significant difference in mean RR interval between the subacute and chronic phase of MI (875 ± 145 versus 859 ± 122 ms). Indices of HRV increased significantly during the observation period (SDNN: from 88.8 ± 26.8 to 116.0 ± 35.7 ms, P < 0.001; SDNNi: from 37.9 ± 15.9 to 46.0 ± 16.3 ms, P < 0.001; SDANN: from 79.6 ± 34.7 to 105.6 ± 35.4 ms, P < 0.001). In contrast, there were no significant changes in indices of HRT (turbulence onset: from −0.008 ± 0.022 to −0.012 ± 0.025%; turbulence slope: from 7.78 ± 5.9 to 8.06 ± 6.8 ms/beat). In contrast to reflex autonomic activity, there was a significant recovery of tonic autonomic activity within 12 months after MI. These different patterns of recovery of reflex versus tonic cardiac autonomic control after MI need to be considered when risk stratifying post‐MI patients.

Inadequate ICD Discharges Due to Diaphragmatic Electromyopotential Oversensing as the First Sign of Right Ventricular Lead Perforation

Right ventricular lead perforation, when acute, is a rare but potentially life‐threatening complication of implantable cardioverter defibrillator (ICD) therapy. We report about a patient with early lead perforation presenting with repetitive ICD discharges due to oversensing of diaphragmatic electromyopotentials and describe the management of this complication.

Continuous Holter telemetry of atrial electrograms and marker annotations using a common Holter recording system: Impact on Holter electrocardiogram interpretation in patients with dual chamber pacemakers

WIEGAND, U.K.H., et al.: Continuous Holter Telemetry of Atrial Electrograms and Marker Annotations Using a Common Holter Recording System: Impact on Holter Electrocardiogram Interpretation in Patients with Dual Chamber Pacemakers. The impact of continuous telemetry of atrial electrogram and marker annotations on Holter ECG interpretation was assessed in 98 patients with bipolar dual chamber pacemakers (VDD pacemakers n = 29, DDD(R) systems n = 69). Atrial electrogram and marker annotations were continuously sampled by a telemetry coil that was externally positioned on the pacemaker pocket, amplified, and transduced to a three‐channel Holter ECG recorder in addition to an ECG recording. Holter tapes were analyzed by two experienced investigators for quality of P wave recognition and episodes suspicious of pacemaker dysfunction. Initially, only the ECG channel was analyzed. Thereafter, results were compared to those achieved on the basis of the complete recording including atrial electrogram and marker annotations. Recognition of atrial rhythm was markedly improved by Holter telemetry. During 99.3% of recording time telemetry showed a satisfying quality, whereas ECG alone allowed a reliable P wave recognition only during 84.4% of recording time (P < 0.001). One hundred twenty‐nine episodes suspicious of pacemaker malfunction occurred in 17 of 98 patients. By analysis of ECG, only 78.3% of episodes were concordantly classified by the investigators. However, 98.4% of all episodes were properly identified when atrial electrogram and marker annotations were added to the analysis (P < 0.001). In particular, discrimination between atrial undersensing, sinus bradycardia, and atrial sensed events within the refractory periods was facilitated. Holter telemetry of atrial electrogram and marker annotations facilitates the analysis of Holter ECGs in pacemaker recipients and improves the detection of pacemaker dysfunctions.

R Wave Undersensing Caused by an Algorithm Intended to Enhance Sensing Specifity in an Implantable Cardioverter Defibrillator

This article reports on a case of ventricular undersensing despite normal R wave amplitudes during sinus rhythm in an ICD patient. Undersensing of ventricular signals was noted without any evidence of lead dislocation or variation in signal amplitude. Undersensing was due to an exceptionally small R wave signal width and a feature of the Biotronik sensing algorithm designed to avoid oversensing. This algorithm, intended to enhance the sensing specifity of the device, requires registration of two consecutive points above the maximum programmed sensitivity for a ventricular sense event. After modifying the algorithm to a single point registration undersensing disappeared. (PACE 2003; 26:1776–1777)

Modulation of Cardiac Autonomic Nervous Activity Early after Cardioversion of Atrial Fibrillation by Biphasic Waveform

Background: Imbalance of cardiac autonomic nervous modulation might prominently contribute to early relapses of atrial fibrillation (AF) after cardioversion (CV). The biphasic (Bi) waveform is more effective than the monophasic (Mo) waveform in CV of AF. Whether these waveforms have different effects on autonomic modulation early after CV is unknown.

Diagnosis and management of a massive true inferobasal ventricular aneurysm ante perforationem

Jörg Gellissen, MD Universitätsklinik Schleswig Holstein Campus Lübeck Radiology and Nuclear Medicine Ratzeburger Allee 16