Cardiovascular abnormalities and arrhythmias in patients with Ondine's curse (congenital central hypoventilation) syndrome

Patients with congenital central hypoventilation syndrome (CCHS) (Ondine's curse syndrome) have impaired autonomic control of ventilation with intact voluntary control of respiration. Autonomic dysfunction and cardiac abnormalities are common in CCHS. Bradyarrhythmias are life-threatening and often require pacemaker insertion. We presented a case of a patient with CCHS suffering from long sinus pauses requiring cardiac pacemaker insertion. Patients with CCHS are at risk for pulmonary hypertension and cor pulmonale secondary to chronic hypoxia. Diaphragmatic pacing has been beneficial in some patients with CCHS. In this article, we review concomitant cardiac abnormalities and the occurrence of bradyarrhythmias in patients with CCHS.     

New evidence of baroreflex dysfunction in congenital central hypoventilation syndrome

In this issue of Clinical Science, Trang and co-workers report the results of short-term blood pressure and heart rate variability measurements in patients with congenital central hypoventilation syndrome (CCHS). The results reveal that these young patients disclose signs of vagal withdrawal and baroreflex failure. Baroreflex sensitivity was reduced by one third compared with the matched control subjects; however, patients have a relative preservation of the cardiac and vascular sympathetic function. These findings are clearly new and improve our understanding of CCHS physiopathology. Nevertheless, more research is needed to better delineate the respective contribution of cardiac vagal and sympathetic dysregulation, and the extent to which these abnormalities relate to genetic mutations as well as to clinical status.     

Pacemaker-Mediated Tachycardia from a Single Chamber Temperature Sensitive Pacemaker

This report describes a case of pacemaker-mediated tachycardia from a single chamber temperature sensitive rate modulated pacemaker. The patient experienced diaphragmatic pacing that produced an increase in right ventricular blood temperature. This temperature increase was sensed by the pacemaker and led to sustained upper rate limit pacing. Decreasing the ventricular output to prevent diaphragmatic capture eliminated further episodes of pacemaker-mediated tachycardia.     

延续性运动康复护理对永久人工心脏起搏器植入术患者自我护理能力与生活质量的影响

目的观察延续性运动康复护理对永久人工心脏起搏器植入术患者自我护理能力与生活质量的影响。方法将我院进行永久人工心脏起搏器植入术的100例患者随机分为对照组与观察组,各50例。对照组给予常规护理,观察组给予延续性运动康复护理,比较两组的护理效果。结果护理3、6个月,观察组的心功能指标优于对照组(P<0.05)。观察组的治疗依从性及护理后的自我护理能力、生活质量均优于对照组(P<0.05)。结论延续性运动康复护理对永久人工心脏起搏器植入术患者的护理效果显著,值得应用推广。     

不同起搏方式对患者左心结构与功能及NT-proBNP的影响

【目的】探究生理性起搏（DDD）和非生理性起搏（VVI）对心脏结构及 N-末端脑钠肽前体（NT-proBNP）的影响,并为起搏器植入心脏后的应对策略积累经验。【方法】选取本院心内科于2012年1～12月收治的65例接受起搏器治疗患者,根据不同起搏方式进行分组。其中对照组患者采取 VVI,研究组采取DDD,比较两组患者在植入起搏器前后左心室结构和功能及 NT-proBNP水平变化。【结果】两组患者在植入起搏器前的左心房内径（LAD）、左心室舒张末期内径（LVD）、室间隔厚度（IVST）、左心室后壁厚度（PWT）、左心室射血分数（EF）方面差异无统计学意义（P ＞0．05）;植入起搏器后,研究组 LAD小于对照组（P ＜0．05）,EF高于对照组（P ＜0．05）。两组患者在起搏器植入前 NT-proBNP 值差异无统计学意义（P ＞0．05）;安置起搏器后,研究组 NT-proBNP值低于对照组（P ＜0．05）。【结论】有起搏器植入适应证的患者,为减少起搏对心脏结构和功能的影响,应当选择房室顺序起搏为宜。     

The impact of different positions and thoracial restrains on respiratory induced cardiac motion.

One of the limiting factors for high resolution magnetic resonance coronary angiography (MRCA) is the motion of the heart during breathing. Current approaches use mainly motion correction in one dimension. We aimed to determine the relation between diaphragmatic motion and cardiac motion as well as the potential influence from external restraints reducing thoracical anterior posterior (AP) motion. Four real time navigators were used to collect motion parameters, diaphragmatic cranio-caudal, cardiac cranio-caudal, diaphragmatic anterior-posterior, and thoracical anterior-posterior. Measurements were performed in prone and supine position and supine position with a thorax restraint. In supine, the highest correlation was found between cranio-caudal diaphragmatic and cardiac motion (r2 = 0.71, slope = 0.26; p < 0.05). Prone positioning or external restraints led to significant changes of motion patterns, with a lower correlation between diaphragmatic and cardiac position. External manipulation of breathing by prone positioning or thoracical restraints leads to a less accurate prediction of cardiac position from assessment of diaphragmatic positions compared to standard supine positioning.     

A Method for Estimating Endocardial Electrode Stability

STIRBYS, P., ET AL.: A Method for Estimating Endocardial Electrode Stability. Assessment of cardiac pacing electrode stability following implantation is of major importance. We describe a method of testing electrode stability using a provocative test. The method includes synchronized electrical pacing of the left phrenic nerve by an especially designed external pacemaker. A positive response is abrupt, a diaphragmatic contraction, which in turn induces an abrupt heart movement in its diastole, its relaxation phase. Fifty-six various endocardial electrodes were tested in this fashion. Seven electrodes, one with flange tip, two tined, and four had no fixation dislodged after this pacing test. Insignificant elevation of acute ventricular pacing threshold was observed. While this method appears to be advantageous, additional clinical data is necessary.     

心脏再同步治疗慢性心力衰竭患者的并发症分析

目的探讨心脏再同步治疗(CRT)慢性心力衰竭患者的术中、术后并发症的发生与处理措施。方法CRT植入术者55例,男性38例,女性17例,年龄(62.5±9.6)岁,其中扩张性心肌病(DCM)41例,缺血性心肌病(CHD)11例,Ⅲ度房室传导阻滞伴心脏扩大2例,致密化不全性心肌病1例。NYHA心功能分级均为Ⅲ级-IV级。均成功植入三腔起搏器。术后常规应用标准抗心力衰竭药物,随访2~60(24.9±15.5)个月,观察术中、术后并发症的发生情况及处理效果。结果55例患者中左室电极置入失败1例(1.8%),发生电极导线脱位3例(5.5%),膈肌刺激2例(3.6%),术中急性左心力衰竭竭1例(1.8%),血管迷走反射(VVR)1例(1.8%),均妥善处置,未发生恶性结果。结论CRT植入术术中和术后有可能出现各种并发症,以电极导线脱位最常见;针对不同的情况妥善处理才能充分发挥CRT在心力衰竭治疗中的作用。     

Short-term blood pressure and heart rate variability in congenital central hypoventilation syndrome (Ondine's curse)

The effect of CCHS (congenital central hypoventilation syndrome, or Ondine's curse) on short-term BP (blood pressure) and HR (heart rate) variability was evaluated in 16-year-old subjects presenting a form of CCHS requiring night ventilatory assistance. The 12 patients were compared with 12 age- and gender-matched healthy volunteers. Recordings were obtained during daytime while the subjects were breathing spontaneously. Continuous BP was measured with a Finapres device in the supine, head-up tilt and standing positions. The manoeuvre of actively standing was also analysed. HR levels were elevated in CCHS subjects at supine rest (+23%) with a reduced HR overall variability (-88%). The low- and high-frequency components of HR variability were affected. BP levels were preserved at rest, but the manoeuvres demonstrated a limited capacity to elevate BP. There was no overshoot in BP during the manoeuvre of actively standing, and steady standing BP levels in patients were not higher than supine BP levels as usually observed in healthy controls. The spontaneous baroreflex sensitivity estimated using the sequence technique or the cross-spectral analysis fell in the patients to approx. one-third of the sensitivity estimated in the healthy controls whatever the position. This cardiovascular profile suggests a predominant vagal dysfunction with signs of vagal withdrawal and baroreflex failure, and relative preservation of the cardiac and vascular sympathetic function. It is likely that the impaired ontogeny of the visceral reflexes, considered now to cause CCHS syndrome, includes the baroreceptive pathway and mainly its vagal component.     

体外充电植入式人工心脏起搏器的设计

背景：人工心脏起搏器长期植入人体,使用寿命至关重要,目前尚没有可充电的植入式人工心脏起搏器问世。目的：探讨植入式人工心脏起搏器体外充电技术,以期降低人工心脏起搏器寿命对电池能量的依赖。方法：利用某种对人体无创、无害的介质,把体外能量隔离传输给植入体内的接收转换装置,进而对人工心脏起搏器可充电电池的能量给予补充,以延长使用寿命。结果与结论：试制了可充电人工心脏起搏器实验样机,完成了一期动物实验,同时以超声波为能量传输载体进行了隔离无刨充电试验,对相关技术做了探讨。     

临床护理路径在心脏起搏器安置术健康教育中的应用

[目的]探讨临床护理路径(CPN)在人工心脏起搏器病人健康教育中的应用效果。[方法]将40例人工心脏起搏器安置术病人随机分为两组,对照组采用传统健康教育方法,实验组应用CPN实施健康教育。[结果]实验组病人满意度与对照组比较差异有统计学意义(P<0.05)。[结论]应用CPN对人工心脏起搏器安置术病人实施健康教育可提高病人对护理工作的满意度。     

临床路径在心脏起搏器安置术患者护理中的应用与效果

目的 探讨临床路径在心脏起搏器安置术患者护理中的应用方法与效果.方法 选择2009年3月至2011年3月43例行心脏起搏器安置术的患者为试验组,采用临床路径进行护理;选择2007年1月至2009年2月34例行心脏起搏器安置术患者为对照组,采用传统的常规护理计划.比较两组的住院天数、住院费用和护理满意程度及术后发生尿潴留的情况.结果 试验组平均住院天数少于对照组(P＜0.05),术后发生尿潴留的发生率低于对照组(P＜0.05),患者对护理满意率高于对照组(P,＜0.05);试验组与对照组在住院费用方面差异无统计学意义(P＞0.05).结论 心脏起搏器安置术患者采用临床路径护理可缩短住院天数,减少术后并发症的发生,提高患者对护理工作的满意度.     

临床护理路径结合个案管理模式在永久性起搏器植入患者中的应用

目的：探讨临床护理路径结合个案管理模式在永久性起搏器植入患者中的应用效果。方法选择行永久性起搏器植入术的60例患者,随机分为观察组和对照组各30例。观察组患者实施临床护理路径结合个案管理模式,对照组接受传统护理模式。对比两组的住院天数、并发症发生例数、疾病知识问卷得分、患者满意度及焦虑水平。结果观察组与对照组相比,住院天数少,并发症例数少,疾病知识问卷得分高,患者满意度高,差异均有统计学意义(P<0.05);两组患者焦虑水平在入院时差异无统计学意义(P>0.05),出院时两组比较差异均有统计学意义(P<0.05)。结论在永久性起搏器植入患者中实施临床护理路径与个案管理相结合的模式,可以明显缩短住院天数,减少并发症,提高患者疾病知识掌握程度,提高患者满意度,减轻患者焦虑水平。     

心理干预对安置人工心脏起搏器患者术前焦虑的影响

目的:探讨心理干预对安置人工心脏起搏器患者术前焦虑的影响。方法:随机将40例接受人工心脏起搏器安置的患者分为观察组(20例)和对照组(20例),对照组接受一般的心理护理,观察组术前接受心理干预,并测定其术前心率、血压、焦虑值等各项指标。结果:心理干预后观察组术前心率、血压、焦虑值均显著低于对照组(P<0.05)。结论:心理干预在缓解安置人工心脏起搏器患者术前焦虑的效果好于一般的心理护理。     

A most unusual pacemaker

We present a case of pacemaker artifact on 12-lead electrocardiogram that was initially interpreted as malfunction of the patient's dual-chamber cardiac pacemaker. It was ultimately determined to arise from an extracardiac gastric pacemaker, which had been inserted for refractory, severe diabetic gastroparesis. Proper functioning of both devices was confirmed, and settings were adjusted to test for interdevice interference. This is a report of a patient with both cardiac pacemaker and a gastric pacemaker. We review the literature on patients with multiple pacemaker devices, and conclude with several practical considerations for their care.     

Permanent cardiac pacemakers: issues relevant to the emergency physician, part II.

Many people benefit from the implantation of cardiac pacemakers for management of certain cardiac dysrhythmias. These patients are seen regularly in the Emergency Department with a variety of pacemaker complications and malfunctions. The presence of a pacemaker may also affect management of unrelated medical problems. This, the second of a two-part series, covers the causes, diagnosis, and management of pacemaker malfunction; the pacemaker syndrome; the pacemaker Twiddler's syndrome; and other considerations in the paced patient including diagnosis of acute myocardial infarction, ACLS protocols, trauma, and sources of interference.     

Activity-mode cardiac pacing: clinical considerations

In the past, pacemaker candidates with "chronotropic incompetence" or chronic atrial arrhythmias have been treated with fixed-rate cardiac pacing. During physical exertion, however, increased cardiac output is often limited by this fixed rate. A physiologic pacemaker that increases the cardiac pacing rate as a response to physical activity is now available. The benefits of this pacemaker are increased heart rate during physical activity and increased exercise tolerance.     

Delayed perforation of right ventricle with cardiac tamponade: a complication of pacemaker implantation.

We report a case of delayed cardiac tamponade that resulted from pacemaker implantation in the emergency room of a large urban hospital. A 19-year-old male patient with a pacemaker implanted 10 days earlier suffered from delayed perforation of the right ventricle with cardiac tamponade. A review of the literature revealed that cardiac tamponade is a rare complication of pacemaker implantation. Pacemakers should only be implanted by physicians with relevant experience, and emergency room physicians should be aware of the possibility of the associated complications and be prepared to treat them.     

Pacing in high field cardiac magnetic resonance imaging:

Currently, cardiac MRI is contraindicated in patients with an implanted pacemaker or ICD due to safety hazards. However, MRI is promising to play a key role in cardiac diagnostics in near future. This study examined a rat with an implanted pacemaker pacing at a rate of 460/min with high field cardiac MRI. This study showed that pacing during cardiac imaging at 7 Tesla was possible. The pacemaker program was not disturbed by the high field or the strong gradients (maximum dB/dt 400 mT/s). The only noticeable effect on the MRI signal was a signal void of 2 cm around the device.