Frank Eberhardt

Publications of Frank Eberhardt

• AV interval optimization using pressure volume loops in dual chamber pacemaker patients with maintained systolic left ventricular function.

  Authors: Frank Eberhardt, Thorsten Hanke, Joern Fitschen, Matthias Heringlake, Frank Bode, Heribert Schunkert, Uwe K H Wiegand

  Clinical research in cardiology : official journal of the German Cardiac Society. 03/2012;

  BACKGROUND: Atrioventricular (AV) interval optimization is often deemed too time-consuming in dual-chamber pacemaker patients with maintained LV function. Thus the majority of patients are left atBACKGROUND: Atrioventricular (AV) interval optimization is often deemed too time-consuming in dual-chamber pacemaker patients with maintained LV function. Thus the majority of patients are left at their default AV interval. OBJECTIVE: To quantify the magnitude of hemodynamic improvement following AV interval optimization in chronically paced dual chamber pacemaker patients. PATIENTS AND METHODS: A pressure volume catheter was placed in the left ventricle of 19 patients with chronic dual chamber pacing and an ejection fraction >45 % undergoing elective coronary angiography. AV interval was varied in 10 ms steps from 80 to 300 ms, and pressure volume loops were recorded during breath hold. RESULTS: The average optimal AV interval was 152 ± 39 ms compared to 155 ± 8 ms for the average default AV interval (range 100-240 ms). The average improvement in stroke work following AV interval optimization was 935 ± 760 mmHg/ml (range 0-2,908; p < 0.001), which translates into an average improvement of 14 ± 9 % (range 0-28). A 10 ms variation of the AV interval changes the average stroke work by 207 ± 162 mmHg/ml. AV interval optimization also leads to improved systolic dyssynchrony indices (17.7 ± 7.0 vs. 19.4 ± 7.1 %; p = 0.01). CONCLUSION: The overall hemodynamic effect of AV interval optimization in patients with maintained LV function is in the same range as for patients undergoing cardiac resynchronization therapy for several parameters. The positive effect of AV interval optimization also applies to patients who have been chronically paced for years.

• 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.

  Authors: Thorsten Hanke, Martin Misfeld, Matthias Heringlake, Jan J Schreuder, Uwe K H Wiegand, Frank Eberhardt

  The Journal of thoracic and cardiovascular surgery. 08/2009; 138(1):148-56.

  OBJECTIVE: Patients with severely reduced left ventricular function undergoing coronary artery bypass grafting have increased complication rates. We hypothesized that temporary postoperative atrialOBJECTIVE: 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.

• 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.

  Authors: Frank Eberhardt, Matthias Heringlake, Maximilian S Massalme, Anika Dyllus, Martin Misfeld, Hans H Sievers, Uwe K H Wiegand, Thorsten Hanke

  The Journal of thoracic and cardiovascular surgery. 07/2009; 137(6):1461-7.

  OBJECTIVES: Biventricular pacing acutely improves left ventricular function in patients with heart failure and left ventricular dyssynchrony. Pressure-volume loop analysis has shown acuteOBJECTIVES: 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.

• Continuous positive airway pressure therapy decreases evening cortisol concentrations in patients with severe obstructive sleep apnea.

  Authors: Andre Schmoller, Frank Eberhardt, Kamila Jauch-Chara, Ulrich Schweiger, Peter Zabel, Achim Peters, Bernd Schultes, Kerstin M Oltmanns

  Metabolism: clinical and experimental. 05/2009;

  Patients with obstructive sleep apnea syndrome (OSAS) show recurrent episodes of nightly hypoxic stress. The purpose of this study is the detection of alterations of thePatients with obstructive sleep apnea syndrome (OSAS) show recurrent episodes of nightly hypoxic stress. The purpose of this study is the detection of alterations of the hypothalamic-pituitary-adrenal stress axis in OSAS patients before and after continuous positive airway pressure (CPAP) therapy. An activation of the hypothalamic-pituitary-adrenal axis was proposed because of the nightly hypoxic stress in these patients, but previous studies were not conclusive. Here we hypothesize that CPAP therapy decreases salivary cortisol concentrations in patients with severe OSAS. We performed a clinical within-subject study including 50 patients with newly diagnosed OSAS and an apnea-hypopnea index greater than or equal to 40 h(-1). Diurnal profiles of salivary cortisol concentrations were compiled before and after 3 months of treatment with CPAP. Therefore, 6 cortisol samples were collected: before and after lunch, in the evening, the next morning after awakening, and before and after breakfast. Thirty-eight patients returned after 3 months of CPAP therapy for follow-up. According to the reference range for healthy subjects, cortisol values were not pathologically increased. Analysis of variance revealed a significant effect of CPAP therapy on diurnal cortisol profiles (P = .048). Subjects with severe OSAS showed a decrease (3.04 +/- 0.55 nmol L(-1) pre-CPAP vs 2.48 +/- 0.78 nmol L(-1) post-CPAP, P = .038) of evening cortisol levels after CPAP treatment, whereas prelunch levels were increased after CPAP therapy (7.18 +/- 0.83 nmol L(-1) pre-CPAP vs 10.22 +/- 1.10 nmol L(-1) post-CPAP, P = .044). Our results show that CPAP therapy decreases evening cortisol concentrations in patients with severe OSAS. These data suggest that OSAS may increase the cortisol nadir that is reversed after CPAP therapy.

• Lack of agreement between thermodilution and electrical velocimetry cardiac output measurements.

  Authors: Matthias Heringlake, Ulrich Handke, Thorsten Hanke, Frank Eberhardt, Jan Schumacher, Hartmut Gehring, Hermann Heinze

  Intensive care medicine. 12/2007; 33(12):2168-72.

  OBJECTIVE: The modified algorithm for the non-invasive determination of cardiac output (CO) by electrical bioimpedance-electrical velocimetry (EV)-has been reported to give reliable results inOBJECTIVE: The modified algorithm for the non-invasive determination of cardiac output (CO) by electrical bioimpedance-electrical velocimetry (EV)-has been reported to give reliable results in comparison with echocardiography and pulmonary arterial thermodilution (PA-TD) in patients either before or after cardiac surgery. The present study was designed to determine whether EV-CO measurements reflect intraindividual changes in CO during cardiac surgery. DESIGN: Prospective, observational study. SETTING: Operating room (OR) and intensive care unit (ICU) of a university hospital. PATIENTS: Twenty-nine patients undergoing elective cardiac surgery. INTERVENTIONS: None. MEASUREMENTS: CO was determined simultaneously by PA-TD and EV after induction of anesthesia (t1) and 4.9+/-3.5 h after ICU admission (t2). RESULTS: TD-CO was 3.9+/-1.4 and 5.4+/-1.1 l/min at t1 and t2 (p < 0.0001). EV-CO was 4.3+/-1.1 and 4.9+/-1.5 l/min at t1 and t2 (p = 0.013). Bland-Altman analysis showed a bias of -0.4 l/min and 0.4 l/min and a precision of 3.2 and 3.6 l/min (34.3% and 67.4%) at t1 and t2, respectively. Analysis of the individual pre- to postoperative changes in CO with both methods revealed bidirectional changes in n = 12 patients and unidirectional changes with a difference greater than 50% and less than 50% in n = 9 and n = 8 patients, respectively. CONCLUSIONS: The disagreement between PA-TD and EV-CO measurements after anesthesia induction and after ICU admission, as well as the fact that thoracic bioimpedance did not adequately reflect pre- to postoperative changes in CO, questions the reliability of EV-CO measurements in cardiac surgery patients and contrasts sharply with previous studies.

• Morphology-enhanced atrial event classification improves sensing in pacemakers.

  Authors: Thorsten Lewalter, Ype Tuininga, Gerd Fröhlig, Susann Remerie, Frank Eberhardt, Jörg Schmidt, Chris Van Groeningen, Peter Wohlgemuth

  Pacing and clinical electrophysiology : PACE. 12/2007; 30(12):1455-63.

  BACKGROUND: In atrial-based pacing, appropriate therapy and reliable diagnostics depend on detection and discrimination of atrial signals. Accurate classification of atrial events is mainlyBACKGROUND: In atrial-based pacing, appropriate therapy and reliable diagnostics depend on detection and discrimination of atrial signals. Accurate classification of atrial events is mainly confounded by oversensing of ventricular far-field R-wave signals (FFRW), but attempts to reject FFRWs by manipulating atrial sensitivity and/or postventricular atrial blanking period (PVAB) may result in undersensing (especially of atrial fibrillation, AF) or in 2:1 atrial flutter detection. The objective of this study is therefore to evaluate if such methods can be improved by morphology-enhanced atrial event classification (MORPH). METHODS: Twenty-four-hour ambulatory atrial electrograms were recorded from continuous telemetry of digital pacemakers. Half of the recording was used for collecting two individual morphology parameters that discriminated P-waves from FFRWs in every patient (learning phase). The other half was used to test the MORPH algorithm against traditional methods (classification phase). RESULTS: In 44/48 patients, data were suitable for analysis. Average P and FFRW amplitudes were 1.96 mV versus 0.61 mV (P < 0.001). The interval between ventricular events and FFRW oversensing (VA interval) averaged at 14 ms during sensing and at 118 ms during pacing in the ventricle. Compared to nominal ("Factory") settings, the MORPH algorithm improved the sensitivity for P-wave recognition from 97.2% to 99.2%, the specificity from 91.9% to 99.96%, and the accuracy from 95.3% to 99.4% (P < 0.01 for all). CONCLUSIONS: By improving atrial signal discrimination, morphology analysis of atrial electrograms allows for high atrial sensitivity settings, and potentially improves the reliability of atrial arrhythmia diagnostics in heart rhythm devices.

• Incidence and significance of far-field R wave sensing in a VDD-implantable cardioverter defibrillator.

  Authors: Frank Eberhardt, Andreas Schuchert, Dietmar Schmitz, Thomas Zerm, Sabine Mitzenheim, Uwe Kh Wiegand

  Pacing and clinical electrophysiology : PACE. 04/2007; 30(3):395-403.

  BACKGROUND: A VDD-implantable cardioverter-defibrillator (ICD) provides atrioventricular (AV) synchronous stimulation when necessary and incorporates the advantages of dual chamber arrhythmiaBACKGROUND: A VDD-implantable cardioverter-defibrillator (ICD) provides atrioventricular (AV) synchronous stimulation when necessary and incorporates the advantages of dual chamber arrhythmia discrimination algorithms both at potentially lower costs and less periprocedural complications than a DDD-ICD system. A prerequisite for correct dual chamber ICD function is reliable atrial sensing. METHODS: We evaluated atrial near- and ventricular far-field sensing and its impact on the dual-chamber detection algorithm in 106 patients with a single-lead VDD-ICD during a 12-month follow-up period. RESULTS: Six hundred and thirty-nine follow-ups were included. Mean near-field amplitude was 3.82 +/- 1.76 mV; mean far-field amplitude was 0.31 +/- 0.15 mV. 46% of patients had far-fields >0.35 mV and 35% of patients showed atrial EGM markers corresponding to a ventricular far-field in at least one follow-up. Six hundred and forty-five tachycardia episodes were evaluated. Due to far-field sensing, three of 66 episodes (4.5%) of sinus tachycardia were misclassified as ventricular tachycardia (VT), leading to antitachycardia therapies. Delayed detection of VT was seen in a 12 of 323 episodes (3.7%) in five of 62 patients (8%) having VT events (delay 6.4 +/- 6.0 seconds (range 2-24 seconds)). Stable far-field amplitudes <0.2 mV in a follow-up had a high negative predictive value for the occurrence of malfunction during tachycardia-conversely, high far-field amplitudes or a high incidence of far-field markers are only moderately correlated with malfunction. CONCLUSIONS: Ventricular far-field sensing in a VDD-ICD is not uncommon, however, tachycardia detection by the dual chamber algorithm is not seriously impaired by far-field sensing.

• Modulation of cardiac autonomic nervous activity early after cardioversion of atrial fibrillation by biphasic waveform.

  Authors: Jasmin Ortak, Franziska Kurtz, Ann-Sophie Krenzien, Nina Janca, Iris Wilke, Melanie Barantke, Frank Eberhardt, Uwe K H Wiegand, Heribert Schunkert, Hendrik Bonnemeier

  Pacing and clinical electrophysiology : PACE. 02/2007; 30 Suppl 1:S207-11.

  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 moreBACKGROUND: 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. METHODS: We investigated 171 consecutive patients after successful electrical CV (mean age 65.4 years, 82% male, 80% structural heart disease). Bi waveform was used in 89, Mo waveform in 82. Heart rate variability (HRV) was analyzed from 24-hour Holter recordings, started directly after CV. RESULTS: Mean delivered total energy was significantly lower in the Bi group (Bi 223 +/- 163 W, Mo 355 +/- 211 W, P < 0.001). Mean RR interval decreased within 5 hours after CV and increased again within the remaining hours, without significant differences between Bi and Mo groups. Time courses of time domain parameters of HRV revealed Bi profiles with the lowest levels 6 hours after CV in both groups. However, the hourly values of HRV were significantly higher in the Bi subgroup. CONCLUSION: Our study indicates that waveform and total delivered energy significantly influence autonomic modulation of the sinus node in the early phase after CV of AF. In contrast to Bi CV, Mo CV is characterized by a significant decrease of cardiac vagal modulation, which may have an arrhythmic effect by increasing the degree of early electrical stunning after CV of AF.

• Feasibility of temporary biventricular pacing in patients with reduced left ventricular function after coronary artery bypass grafting.

  Authors: Frank Eberhardt, Thorsten Hanke, Mathias Heringlake, Maximilian S Massalme, Matthias Bechtel, Martin Misfeld, Uwe K H Wiegand

  Pacing and clinical electrophysiology : PACE. 02/2007; 30 Suppl 1:S50-3.

  BACKGROUND AND METHODS: Biventricular pacing improves hemodynamics after weaning from cardiopulmonary bypass in patients with severely reduced left ventricular (LV) function undergoing coronaryBACKGROUND AND METHODS: Biventricular pacing improves hemodynamics after weaning from cardiopulmonary bypass in patients with severely reduced left ventricular (LV) function undergoing coronary artery bypass grafting (CABG). We examined the feasibility of temporary biventricular pacing for 96 hours postoperatively. Unipolar epicardial wires were placed on the roof of the right atrium (RA), the right ventricular (RV) outflow tract, and the LV free lateral wall and connected to an external pacing device in 51 patients (mean LV ejection fraction 35 +/- 4%). Pacing and sensing thresholds, lead survival and incidence of pacemaker dysfunction were determined. RESULTS: Atrial and RV pacing thresholds increased significantly by the 4th postoperative day, from 1.6 +/- 0.2 to 2.5 +/- 0.3 V at 0.5 ms (P = 0.03) at the RA, 1.4 +/- 0.3 V to 2.7 +/- 0.4 mV (P = 0.01) at the RV, and 1.9 +/- 0.6 V to 2.9 +/- 0.7 mV (P = 0.3) at the LV, while sensing thresholds decreased from 2.0 +/- 0.2 to 1.7 +/- 0.2 mV (P = 0.18) at the RA, 7.2 +/- 0.8 to 5.1 +/- 0.7 mV (P = 0.05) at the RV, and 9.4 +/- 1.3 to 5.5 +/- 1.1 mV (P = 0.02) at the LV. The cumulative overall incidence of lead failure was 24% by the 4th postoperative day, and was similar at the RV and LV. We observed no ventricular proarrhythmia due to pacing or temporary pacemaker malfunction. CONCLUSIONS: Biventricular pacing after CABG using a standard external pacing system was feasible and safe.

• Inadequate ICD discharges due to diaphragmatic electromyopotential oversensing as the first sign of right ventricular lead perforation.

  Authors: Uwe K H Wiegand, Iris Wilke, Hendrik Bonnemeier, Frank Eberhardt, Frank Bode

  Pacing and clinical electrophysiology : PACE. 11/2006; 29(10):1176-8.

  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 earlyRight 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.

• Atrial near-field and ventricular far-field analysis by automated signal processing at rest and during exercise.

  Authors: Frank Eberhardt, Hendrik Bonnemeier, Martin Lipphardt, Ulrich G Hofmann, Heribert Schunkert, Uwe K H Wiegand

  Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology, Inc. 05/2006; 11(2):118-26.

  INTRODUCTION: Sophisticated monitoring of atrial activity is a prerequisite for modern pacemaker therapy. Ideally, near-fields and ventricular far-fields ought to be distinguished by beat-to-beatINTRODUCTION: Sophisticated monitoring of atrial activity is a prerequisite for modern pacemaker therapy. Ideally, near-fields and ventricular far-fields ought to be distinguished by beat-to-beat template analysis of the atrial signal. A prerequisite is that atrial signals are stable under different conditions. METHODS AND RESULTS: A Matlab routine was developed to analyze atrial electrograms of 23 patients at least 3 months after implantation of a dual chamber pacemaker under several conditions including at rest, bipolar at rest, in an upright position, during treadmill exercise, and postexercise. A near-field and far-field template was created and amplitudes, widths, and slew rates were measured. In bipolar configuration, near-field amplitude at rest was 3.04 +/- 0.94 mV (unipolar)/3.36 +/- 1.0 mV (bipolar) versus 3.18 +/- 1.0 mV (bipolar) at peak exercise. Far-field amplitude at rest was 1.66 +/- 1.18 (unipolar)/0.47 +/- 0.27 mV (bipolar) and 0.41 +/- 0.21 mV (bipolar) at peak exercise (n.s. for bipolar measurements). No overall significant changes were observed for near- and far-field widths and slew rates during exercise. Shorter tip-ring distances of the atrial bipole, lead position, and the presence of sinus node disease did not have any impact on overall near- and far-field signal characteristics. Intraindividual differences between rest and peak exercise were moderate (range: near-field +0.15 to -0.54 mV; range: far-field +0.05 to -0.18 mV). CONCLUSIONS: Atrial near and far fields can be automatically classified and quantified by automated signal processing. Signals did not change during exercise or change of posture. This is a prerequisite for the implementation of beat-to-beat template analysis into pacemakers.

• Accelerated idioventricular rhythm in the post-thrombolytic era: incidence, prognostic implications, and modulating mechanisms after direct percutaneous coronary intervention.

  Authors: Hendrik Bonnemeier, Jasmin Ortak, Uwe K H Wiegand, Frank Eberhardt, Frank Bode, Heribert Schunkert, Hugo A Katus, Gert Richardt

  Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology, Inc. 05/2005; 10(2):179-87.

  BACKGROUND: In the thrombolytic era, the occurrence of accelerated idioventricular rhythm (AIR) has been proposed to be a specific marker for successful reperfusion. The incidence, prognosticBACKGROUND: In the thrombolytic era, the occurrence of accelerated idioventricular rhythm (AIR) has been proposed to be a specific marker for successful reperfusion. The incidence, prognostic implications, and potential modulating mechanisms of AIR after successful restoration of antegrade flow by means of modern reperfusion therapy (i.e., direct percutaneous coronary intervention (PCI)) has thus far not been investigated. METHODS: We prospectively investigated 125 consecutive patients undergoing direct PCI for a first acute myocardial infarction (AMI). The incidence of AIR was determined from 24-hour Holter monitoring, initiated prior to PCI. RESULTS: AIR appeared in 19 patients (15.2%). There were no significant differences between patients with or without AIR regarding baseline clinical characteristics. The incidence of AIR was not different between patients with TIMI 2 and 3 flow (13% vs 16%). There were no differences in the incidence of major cardiac events within 12-month follow-up in patients with and without AIR. Patients with AIR exhibited higher mean R-R intervals (mean 24-hour R-R interval: 871.3 +/- 121 vs 796.4 +/- 100 ms, P < 0.01), higher hourly mean values of heart rate variability (SDNN, 64.7 +/- 26 vs 49.4 +/- 20 ms, P < 0.01; rMSSD, 29.3 +/- 15 vs 22.0 +/- 12 ms, P < 0.01) and lower serum norepinephrine concentrations (60 minute after PCI, 478.9 +/- 357 vs 649.0 +/- 499 pg/ml, P < 0.05). CONCLUSIONS: Our findings indicate that AIR is an nonspecific marker for reperfusion of the infarct-related artery in AMI and thus, predate previous observations of the thrombolytic era. Even though, AIR was associated with higher tonic vagal tone and lower sympathetic activity, the occurrence of AIR had no prognostic impact on the clinical course and was not able to discriminate between complete and incomplete reperfusion.

• Changes in heart rate, heart rate variability, and heart rate turbulence during evolving reperfused myocardial infarction.

  Authors: Jasmin Ortak, Gunther Weitz, Uwe K H Wiegand, Frank Bode, Frank Eberhardt, Hugo A Katus, Gert Richardt, Heribert Schunkert, Hendrik Bonnemeier

  Pacing and clinical electrophysiology : PACE. 02/2005; 28 Suppl 1:S227-32.

  Depressed cardiac parasympathetic activity is associated with electrical instability and adverse outcomes after myocardial infarction (MI). Heart rate turbulence (HRT), reflecting reflex vagalDepressed 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.

• Pocket hematoma after pacemaker or implantable cardioverter defibrillator surgery: influence of patient morbidity, operation strategy, and perioperative antiplatelet/anticoagulation therapy.

  Authors: Uwe K H Wiegand, Dominik LeJeune, Frank Boguschewski, Hendrik Bonnemeier, Frank Eberhardt, Heribert Schunkert, Frank Bode

  Chest. 11/2004; 126(4):1177-86.

  STUDY OBJECTIVES: Pocket hematoma is a common complication after pacemaker or implantable cardioverter defibrillator (ICD) implantation. Thus, we investigated the influence of patient comorbidity,STUDY OBJECTIVES: Pocket hematoma is a common complication after pacemaker or implantable cardioverter defibrillator (ICD) implantation. Thus, we investigated the influence of patient comorbidity, implantation strategy, operator experience, antiplatelet therapy, and anticoagulation therapy on hematoma rate. DESIGN: Between 1990 and 2002, a total of 3,164 devices (pectoral pacemakers, 2,792; ICDs, 372) were implanted at our institution. Predictors of hematoma occurrence were determined prospectively and were analyzed by multivariate regression analysis. Operator experience was graded by individual implantation number, as follows: low, < 50; medium, 50 to 100; and high, > 100. RESULTS: The incidence of pocket hematoma was 4.9%, leading to prolonged hospitalization in 2.0% of all patients. Reoperation for pocket hematoma was required in 1.0% of patients. High-dose heparinization (hazard ratio [HR], 4.2), combined acetylsalicylic acid (ASA)/thienopyridine treatment after coronary stenting (HR, 5.2), and low operator experience (HR, 1.6) were independently predictive of hematoma development. Therapy with ASA alone did not increase the hematoma rate compared to patients who did receive antiplatelet or anticoagulation therapy (3.1% vs 2.5%, respectively; difference not significant). In patients with nonvalvular atrial fibrillation, postoperative high-dose heparinization substantially increased the hematoma rate (10.7% vs 2.9%, respectively; p < 0.001) without reducing the rate of arterial embolism within the first month after implantation (0.18% vs 0.21%, respectively; difference not significant). The infection rate (0.28% within 3 months after implantation) was not influenced by the presence of the pocket hematoma. CONCLUSIONS: The use of high-dose heparinization and combined ASA/thienopyridine treatment are highly predictive for the occurrence of intraoperative bleeding and pocket hematoma in patients who have undergone pacemaker and ICD surgery. We propose recommendations for the management of antiplatelet and anticoagulation therapy in patients undergoing these interventions.

• R wave undersensing caused by an algorithm intended to enhance sensing specificity in an implantable cardioverter defibrillator.

  Authors: Frank Eberhardt, Werner Peters, Frank Bode, Uwe K H Wiegand

  Pacing and clinical electrophysiology : PACE. 09/2003; 26(8):1776-7.

  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 evidenceThis 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 specificity 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.

• 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.

  Authors: Uwe K H Wiegand, Hendrik Bonnemeier, Frank Bode, Frank Eberhardt, Julian K R Chun, Hugo A Katus, Werner Peters

  Pacing and clinical electrophysiology : PACE. 12/2002; 25(12):1724-30.

  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,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.