Behavior of a Respiratory Driven Pacemaker and Direct Respiratory Measurements

In 10 patients with a mean age of 76 +/- 8 years, a rate responsive pacemaker (Meta-MV, Telectronics) was implanted in the left pectoral site. An exercise test was performed in SSI ("adaptive") mode, allowing the device to measure the changes in thoracic impedance. The "slope number" at maximal exercise was chosen to program the pacemaker for a second exercise test in rate responsive mode. Direct measurements of respiratory rate and minute volume were correlated with the pacing rate. After 1 minute of exercise, pacing rate increased by 6% and it decreased smoothly after maximal exercise. The programmed maximal rate was reached at the maximum exercise level in six patients. During 24-hour Holter recording, the mean maximal pacing rate was 103 +/- 18 beats/min. For individual patients, a good correlation of pacing rate with respiratory rate (r = 0.757), oxygen consumption (r = 0.731), and minute volume (r = 0.800) was observed. The data from the entire group showed a highly significant correlation of changes in pacing rate and in respiratory parameters for different levels of exercise and recovery. In a subgroup of five patients, the slope numbers at maximal exercise were reproducible after 10 months. It was concluded that minute volume and its changes were recognized in a reliable way by the Meta-MV pacemaker.     

Atrioventricular Conduction After Transcatheter Aortic Valve Implantation and Surgical Aortic Valve Replacement

AV Conduction After TAVI and SAVR . Introduction: Atrioventricular conduction abnormalities (AVCA) may complicate transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR). The aim of this study was to prospectively evaluate AVCA after TAVI and SAVR. Methods and Results: Among 50 patients undergoing TAVI and 25 patients undergoing SAVR a continuous 7‐day Holter electrocardiogram (ECG) was recorded after the procedure. ECGs during TAVI and 12‐lead ECGs before and 1 and 7 days after TAVI and SAVR were analyzed. At baseline, TAVI patients were older (mean 82.1 vs 75.4, P < 0.001), had a longer PR interval (median 200 milliseconds vs 175 milliseconds, P = 0.004) and broader QRS width (median 100 milliseconds vs 80 milliseconds, P = 0.007) than SAVR patients. New AVCA were observed among 29 TAVI patients (58%), mostly new left bundle branch block (76%). Predilatation induced new AVCA in 14 TAVI patients (28%). New AVCA resolved within 24 hours in 15 TAVI patients (30%), and persisted in 14 TAVI (28%) and 3 SAVR patients (12%, P = 0.12). Among patients with persistent QRS width <120 milliseconds during the first 24 hours after TAVI, QRS width remained stable during the remainder of the observation period. During Holter monitoring complete AV block was observed in 4 TAVI patients (8%) and 3 SAVR patients (12%; P = 0.68). Conclusions: Almost half of AVCA during TAVI are induced by predilatation, but half of them resolve within 24 hours. Persistent AVCA are more frequently observed after TAVI than SAVR. If QRS width is below 120 milliseconds the first day after TAVI, the risk of late AVCA seems low. (J Cardiovasc Electrophysiol, Vol. 23 pp. 1115‐1122, October 2012)     

Prophylaxis of infective endocarditis for dental procedures Report of a Working party of the European Society of Cardiology

Bacterial endocarditis still remains a serious disease withsignificant morbidity and mortality. In patients with knownvalve disease, most cases are caused by oral viridans streptococci.These organisms are present in vast numbers on the gum marginsand in gum pockets. They cause transient bacteraemia duringeating and tooth brushing. More substantial, but short-livedbacteraemia can occur during dental treatment such as extractionand scaling. Bacteria may then become attached to abnormal endocardiumleading to the development of infective endocarditis. Prophylaxisof endocarditis during dental procedures in patients with knownvalve disease should thus be aimed at reducing the number ofbacteria entering the blood stream and eliminating those thatget there. This can be sought first by good oro-dental hygieneand secondly by the use of prophylactic antibiotics.In thispaper, we set out simple guidelines for practitioners in thosecountries that do not already have recommendations of theirown. They are based on guidelines already in use in the UnitedKingdom, France, Switzerland and the United Stated(1–4)     

全髋和全膝关节成形术后功能问题和治疗答案

虽接受全髋或全膝关节成形术的多数患者通过常规的术后康复治疗可获得极佳的临床结果，而由各种原因导致的实际功能障碍仍占患者的15％～20％。这些患者对标准的物理治疗方式没有反应，而需要采用超强的处理方案．这些治疗方案包括侵害性和非侵害性治疗。本研究的目的是识别这些功能受限的患者，评估采用定制的治疗方案治疗的结果。我们规定那些不直接与假体相关的软组织问题。通过X线片或通过本文两名作者（M．M．＆G．E．）的专门检查排除了由于力线不良或松动等所有有关假体的问题。我们列出了继全髋关节成形术和全膝关节成形术后的几个功能问题。这些问题涉及到肌无力、肌紧张、肢体不等长和神经问题。