Zeitschrift für Kardiologie
-
Randomized Controlled Trial Comparative Study Clinical Trial
[Nocturnal oxygen administration and cardiac arrhythmias during Cheyne-Stokes respiration in patients with heart failure].
Cheyne-Stokes respiration (CSR) is common during sleep in patients with severe congestive heart failure. It is not clear, if there is a relation between CSR and arrhythmias. Therefore in this study the impact of the nocturnal CSR on ventricular arrhythmias and the heart rate, as well as the influence of nasal nocturnal oxygen on CSR and sleep was studied. ⋯ Due to the high day-today variability these differences were not significant, but the decrease of average nocturnal heart rate with oxygen was (71 +/- 14 vs 68 +/- 14/min; p < 0.05). In conclusion, nocturnal oxygen causes a reduction of CSR, an improvement of sleep and a decrease of arousals. A significant reduction of arrhythmias by nocturnal oxygen could not be proved.
-
Comparative Study
[Comparison of active and passive fixation of steroid emitting atrial electrodes].
Steroid-eluting screw-in leads (CapSure Fix 4068, Medtronic; n = 14) were compared to the same lead as a J-shaped tined electrode (CapSure SP 4524, Medtronic; n = 27, implanted in the atrium in patients receiving dual-chamber pacemakers. Follow-up were at discharge and after 1 month. Implantation (screw-in lead: 84 +/- 18 min; tined lead: 81 +/-29 min) and fluoroscopy times (screw-in lead: 7.3 +/- 4.9 min; tined lead 9.2 +/- 7.0 min) were similar in the two groups. At implant, P-wave amplitudes were similar with 4.8 +/- 1.6 mV (screw-in lead) and 4.0 +/- 2.6 mV (tinted lead), respectively. Compared to tined leads, the screw-in leads had higher pacing thresholds at 0.5 ms pulse duration (screw-in lead: 0.74 +/- 0.32 V; tined lead: 0.55 +/- 0.15 V; p = 0.02) as well as higher impedance (screw-in lead: 566 +/- 93 ohms; tined lead: 470 +/- 99 ohms; p = 0.01). Pulse duration thresholds at 2.5 V pulse amplitude were neither different at discharge (screw-in lead: 0.07 +/- 0.04 ms; tined lead: 0.06 +/- 0.05 ms) nor after 1 month (screw-in lead: 0.09 +/- 0.04 ms; tined lead: 0.06 +/- 0.06 ms). P-wave amplitudes > or = mV were observed at discharge in 14/14 (screw-in lead) 21/27 patients (tined lead), respectively, and after 1 month in 13/14 (screw-in lead) and 22/27 (tined lead) patients, respectively. Impedance of the screw-in lead was significantly higher with 693 +/- 84 ohms at discharge and 691 +/- 79 ohms after 1 month compared to the tined lead with 520 +/- 81 and 574 +/- 62 ohms (p = 0.001). No lead dislodgment was reported during follow-up. ⋯ For the studied steroid-eluting leads active and passive fixation had neither at implantation nor during 1-month follow up any influence on P-wave amplitude. At similar pulse duration thresholds, impedance of the screw-in lead was significantly higher than for the tined lead. Higher impedance additionally reduces pacing current, if similar pacing impulses are delivered.
-
Severe congestive heart failure and cardiogenic shock don't resemble a homogeneous clinical picture, but a syndrome that is based on very different etiologies. What all the etiologies have in common is the inadequate peripheral O2-supply to essential organs with or without signs of severe pulmonary congestion up to pulmonary edema. For prognosis and therapy is a fast diagnostical clarification of the causes crucial. ⋯ First results give rise to optimism to effectively reduce the mortality of congestive heart failure. The combination of these new pharmacological possibilities with interventional transcutaneous applicable assist-systems (aortic counterpulsationpump IABP, hemopump, transcutaneous heart-lung-machine) as well as the transitory application of an artificial heart (Novacor) can possibly increase the success of these therapeutic strategies. So far there are no convincing results shown in the world literature.
-
Dobutamine stress echocardiography has proven to be a method with high diagnostic accuracy in the detection of coronary artery disease. In case of previous myocardial infarction it is of importance to detect additional regions with inducible myocardial ischemia. This study aimed at the detection of inducible ischemia by dobutamine stress echocardiography and stress perfusion scintigraphy in patients without and with previous myocardial infarction. 50 patients without as well as 50 patients with previous transmural myocardial infarction were investigated. In all patients coronary angiography, technetium-99m methoxy-isobutyl-isonitrile (MIBI)-SPECT after bicycle ergometry and dobutamine stress echocardiography (up to 40 mcg/kg/min dobutamine, 1 mg atropine) were performed within 14 days. In patients with previous myocardial infarction dobutamine stress echocardiography and MIBI-SPECT had similar sensitivities (91 vs. 94%, n.s.) and specificities (81 vs. 75%; n.s.) in the detection of significant coronary artery disease. Agreement on the presence or absence of inducible ischemia was 84% (Kappa = 0.60). In patients with previous transmural myocardial infarction sensitivity of stress echocardiography and perfusion scintigraphy in the detection of significant coronary artery disease is lower with 63% and 77%, respectively. In this patient group transient perfusion defects were found more frequently than inducible wall motion abnormalities, 76% and 60%, respectively. There was a lower agreement (76%; Kappa = 0.49) in the detection of abnormal or normal results between dobutamine echocardiography and stress perfusion scintigraphy for this group of patients. ⋯ This study demonstrates high agreement of dobutamine stress echocardiography and stress perfusion scintigraphy in the evaluation of inducible ischemia in patients without previous transmural myocardial infarction and equal diagnostic accuracy in the detection of coronary artery disease. In patients with previous myocardial infarction there is a lower agreement in the interpretation of patients as having ischemia due to negative dobutamine echo results in patients having positive perfusion scintigraphies.