[Cough as a rare symptom of a pacemaker lead perforation]. / Husten als seltenes Symptom einer Schrittmacherelektrodenperforation.

UNLABELLED: Cough is a common symptom in respiratory medicine. We report on a 60-year-old patient, who developed cough after pacemaker implantation. Diagnostic work up yielded malposition of the right-ventricular lead with penetration of the myocardium. Revision of the lead resulted in complete cessation of cough. CONCLUSION: Pacemaker dysfunction and/or malposition of pacemaker lead should be considered in differential diagnosis of cough after pacemaker implantation.

Sleep apnea in heart failure patients.

Growing evidence suggests that there may be a strong pathophysiologic link between congestive heart failure (CHF) and nocturnal breathing disorders due to nocturnal oxygen desaturation, intrathoracic pressure swings and sympathetic activation. It seems that sleep apnea contributes to systolic and diastolic heart failure, reduced left and right ventricular function and arrhythmia (e.g. atrial fibrillation). Therefore treatment of sleep apnea might alleviate cardiac symptoms and improve cardiac function. Nevertheless, the exact role of long term treatment of sleep apnea in heart failure patients remains to be elucidated.

Cardiac chemoreflex sensitivity in critically ill patients.

Chemoreflexes are important mechanisms for regulating ventilatory and cardiovascular function. The aim of this study was to determine the meaning of autonomic dysfunction for the pathophysiology and outcome in critical ill patients. For the determination of the chemoreflex sensitivity (ChRS), the ratio of the RR interval shift and the shift of oxygen partial pressure during a 5-min inhalation of oxygen with a nose mask was formed. Pathological chemoreflex sensitivity was predefined as a ChRS below 3.0 ms/mmHg. Out of the 27 critical ill patients included into the study, 17 had a sepsis and 10 a cardiogenic shock. In these patients, chemoreflex sensitivity was significantly reduced compared with a control group (sepsis: 2.1 +/- 1.68, cardiogenic shock: 0.4 +/- 0.27, controls: 5.0 +/- 2.8 ms/mmHg; P<0.05 vs. sepsis or cardiogenic shock). There was a significant negative correlation (r=-0.6; P<0.01) between the chemoreflex sensitivity and the severity of illness described by the SOFA-score. We conclude that cardiac reflex mechanisms are changed toward increased sympathetic activity reflected by reduced chemoreflex sensitivity in critical ill patients. Moreover, there is a close negative correlation between the ChRS and the SOFA-score.

Obstructive sleep apnea in heart failure patients: evidence for persistent conduction disturbances or sinus node dysfunction.

Bradycardia is a common finding in patients with obstructive sleep apnea and might be pronounced in heart failure patients. The aim of the present study was to determine the relationship between nocturnal hypoxemia, apnea-hypopnea index, and electrophysiological parameters of sinus node and atrioventricular conduction properties. Electrophysiological studies were performed in 12 patients with heart failure. Polygraphic studies were done in all of the patients. Patients with an AHI >10/h were classified as sleep apnea patients. Mild sleep apnea was diagnosed in 50% of the patients (AHI 17.8 +/- 4.4 vs. 5.1 +/- 3.6/h). There were no differences with respect to the resting heart rate, PQ interval, or QRS duration between the two groups. Sinus node recovery time was normal in all of the patients (993 +/-291 vs. 1099 +/-62 ms, P=0.45). There was no abnormal atrioventricular conduction. Nevertheless, sleep apnea patients showed decreased atrioventricular conduction time (AH) intervals (134 +/- 42 vs. 102 +/- 25 ms, P=0.1) and infranodal conduction time (HV) intervals (59 +/- 9 vs. 43 +/- 7 ms, P=0.01). We conclude that mild sleep apnea was not associated with abnormal findings in sinus node function or AV conduction properties in patients with heart failure. Decreased AH/HV intervals might be a consequence of apnea associated sympathetic activation.

Signal-averaged P-wave ECG as a marker of atrial electrical instability in patients with right ventricular dysfunction.

Severe pulmonary hypertension (PAH) leads to right ventricular dysfunction and is associated with different atrial arrhythmias. In PAH patients, the echocardiographic Tei-index is used for monitoring right heart function. The P-wave signal-averaged ECG (SA-ECG) has been shown to have a potential role in identifying patients at risk of developing paroxysmal atrial fibrillation and those likely to change from paroxysmal to chronic atrial fibrillation. The aim of the present study was to define the correlation of the Tei-Index with parameters of P-wave triggered and bidirectional P-wave SA-ECG. A total of 18 patients (14 men, 4 women) with normal sinus rhythm and a mean age of 67+/-10 years (BMI 27.6+/-5.1 kg/m2) were included into the study. Right ventricular (RV) Tei-index was calculated from the sum of isovolumetric contraction time and relaxation time divided by ejection time. Furthermore, P-wave triggered P-wave signal averaged ECG was performed from an X, Y, and Z lead system. The results show that there was a statistically significant correlation between Tei-index and filtered P-wave duration (r=0.53; P=0.023). Teiindex did not correlate with the root mean square voltage of the last 20 ms of the P wave (r=-0.16; P=0.52). In conclusion, a correlation of RV Tei index with P-wave duration indicates that this echocardiographic measurement is not only a marker of right heart function, but also an indicator of electrical instability that could be useful to detect patients at risk for atrial arrhythmias.

Effects of continuous positive airway pressure on exercise capacity in chronic heart failure patients without sleep apnea.

Continuous positive airway pressure (CPAP) is an effective treatment for obstructive sleep apnea. It is known, that there are beneficial effects on cardiac function, which might be explained by suppression of apnea and specific hemodynamic effects of CPAP. Therefore, CPAP might act as an adjunct therapy in heart failure, even in the absence of sleep apnea. In the present study, 11 patients with congestive heart failure (EF=23.1+/-6.9%) without sleep apnea (AHI 3.0+/-1.2/h) were treated with nocturnal CPAP. Cardiopulmonary exercise testing was performed at baseline and after 8.6 +/-1.3 months. All patients underwent heart catheterization and myocardial biopsy to exclude myocarditis at baseline. Five (46%) of the 11 patients did not complete the study because of poor compliance and irregular use of the CPAP device. Six (54%) of the patients used CPAP regularly (>6 h/night) and completed the study. Cardiopulmonary exercise testing showed an improvement of work load (96+/-36 Watt vs. 112+/-34 Watt; P=0.025) and VO2 peak (1227+/-443 ml vs. 1525+/-470 ml; P=0.01). Oxygen-pulse was increased, although that did not reach significance (11.2+/-4.8 ml/beat vs. 12.6+/-3.9 ml/beat). In conclusion, CPAP might have beneficial effects on exercise capacity in patients with congestive heart failure even in the absence of sleep apnea. Nevertheless, poor compliance seems to be a limiting factor.

[Right atrial ablation of ectopic atrial tachycardia using a 20-pole mapping catheter]. / Ablation ektoper rechtsatrialer Tachykardien unter Verwendung eines 20-poligen Mapping-Katheters.

INTRODUCTION: Ectopic atrial tachycardia (EAT) are frequently unresponsive to pharmacological antiarrhythmic therapy. Radiofrequency ablation seems to be a safe approach to treat those arrhythmias. In the present study we report our results of radiofrequency ablation of EAT with a new mapping system (Stablemapr, Medtronic). METHODS: Thirty consecutive patients with right atrial tachycardia were included in the study. In 15 patients (G1) the 20-polar Stablemapr was used for localization of the arrhythmia foci. Data were compared with a control group (G2, n=15), in which mapping was performed conventionally. The demographic characteristics and the distribution of the different cardiac diseases were comparable in both groups. In group 1 the identification of the EAT was facilitated by the placement of the 20-pole mapping catheter in the right atrium. In group 2 point by point measurements were performed to find the earliest local atrial activation compared to a reference electrode in the high right atrium (activation mapping), or foci were identified by analysis of the P-wave morphology during stimulation (pacemapping). RESULTS: It was possible to successfully ablate all atrial tachycardias. The distribution of the foci was similar in both groups (G1/G2): near to the superior (3/5) and inferior (1/0) caval vene ostium, on the free wall (3/3), at the coronary sinus ostium (3/3) and on the interatrial septum (5/4). The mean procedure (G1: 88+/-33 vs G2: 151+/-61 min; p= or <0.05) and fluoroscopic times (G1: 19+/-9 vs G2: 38+/-28 min; p= or <0.05) were significantly shorter in group 1. Moreover, the mean number of radiofrequency applications was reduced significantly by using the new mapping system (G1: 10+/-10 vs G2: 16+/-13; p= or <0.05). CONCLUSION: Radiofrequency ablation of EAT with right atrial focus can be performed safely and successfully using a 20-pole mapping catheter. The greatest advantages compared to conventional mapping and ablation strategies lies in the shortened investigation and fluoroscopic time.