Permanent Pacemaker Implantation Following Cardiac Surgery: Indications and Long-Term Follow-Up

Background: Conduction disturbances requiring permanent pacemaker implantation after heart surgery occur in about 1.5% of patients. Early pacemaker implantation may reduce morbidity and postoperative hospital stay. We reviewed our experience with patients undergoing surgery to try and identify predictors for pacemaker requirements and patients who will remain pacemaker dependent.
Methods: We performed a retrospective review of 4,999 patients undergoing surgery between the years 1993 and 2005. Patient age was 64 ± 12 years, and 71% were males. Coronary bypass was performed in 4,071 (81%), aortic valve replacement in 675 (14%), and mitral valve replacement in 968 (18%) patients.
Results: Seventy-two patients (1.4%) required implantation of a permanent pacemaker after surgery. Indications for pacemaker implantation included complete atrioventricular block in 59, symptomatic bradycardia/slow atrial fibrillation in nine, second-degree atrioventricular block in two, and other conduction disturbances in two patients. Predictors for pacemaker requirement by multivariate analysis were left bundle branch block and aortic valve replacement (P < 0.001). Late follow-up was available in 58 patients, at 72 ± 32 months. Thirty-seven (63%) were pacemaker dependent. Predictors for late pacemaker dependency were third-degree atrioventricular block after surgery and preoperative left bundle branch block (P < 0.001).
Conclusions: Patients at high risk for pacemaker implantation after heart surgery include those with preexisting conduction disturbances, and those undergoing aortic valve replacement. Of those receiving a pacemaker, about one-third will recover at late follow-up. For patients in the high-risk group who are pacemaker dependent after surgery, we recommend implanting a permanent pacemaker at 5 days after surgery, thus enabling early mobilization and early discharge.     

Permanent Pacemaker Implantation Following Aortic Valve Replacement: Current Prevalence and Clinical Predictors

Background: The incidence of conduction disease requiring permanent pacemaker (PPM) implantation following aortic valve replacement (AVR) ranges from 3% to 6%. Data concerning the potential risks for PPM requirement associated with certain valve types have been conflicting and controversial. We sought to evaluate the prevalence, predictors for PPM implantation, and PPM dependency during follow‐up in patients undergoing AVR. Methods: A total of 214 consecutive patients undergoing AVR were studied retrospectively. A total of 207 patients were included in the statistical analysis. Clinical variables including valve size and types were catalogued and the incidence of PPM evaluated. Cardiac rhythm device clinic records were examined and PPM dependency status was catalogued. Multivariate analyses were performed to determine predictors of PPM implantation and PPM dependency during follow‐up. Results: Fifteen patients (7.2%) required PPM postoperatively. After controlling for clinical and surgical characteristics, predictors for PPM included preoperative first‐degree atrioventricular block with and without left anterior fascicular block or intraventricular conduction delay [odd ratios (OR) = 12.5, P = 0.001], cardiac arrest postoperatively (OR = 9.4, P = 0.012), and combined aortic and mitral valve surgery (OR = 11.5, P = 0.027). Aortic valve types did not predict complete heart block (CHB) and PPM implantation. Of those patients who underwent PPM implantation, 70% were classified as PPM dependent during long‐term follow‐up. Conclusion: CHB and PPM implantation continue to be common complications of AVR. Preexisting atrioventricular with intrafascicular or intraventricular conduction disease along with cardiac arrest and dual valve surgery are the most important significant predictors of PPM implantation and PPM dependency during follow‐up. The selection of valve types did not predict conduction disease requiring PPM implantation.     

Incidence and Predictors of Permanent Pacemaker Requirement after Transcatheter Aortic Valve Implantation with a Self‐Expanding Bioprosthesis

Background: Previous reports have suggested the occurrence of cardiac conduction disorders and permanent pacemaker (PPM) requirement after transcatheter aortic valve implantation (TAVI). Based on a single‐center experience, we aim to assess the incidence of postprocedural conduction disorders, need for PPM, and its determinants after TAVI with a self‐expanding bioprosthesis. Methods: From August 2007 to October 2009, 32 consecutive patients underwent TAVI with the Medtronic CoreValve (MCV) System (Medtronic Inc., Minneapolis, MN, USA). Three patients paced at baseline and two cases of procedure‐related mortality were excluded. We analyzed the 12‐lead electrocardiogram at baseline, immediately after procedure and at discharge. Requirements for PPM were documented and potential clinical, electrophysiological, echocardiographic, and procedural predictors of PPM requirement were studied. Results: After TAVI, eight patients (29.6%) required PPM implantation due to high‐grade atrioventricular (AV) block. The prevalence of left bundle branch block increased from 13.8% to 57.7% directly after implantation (P = 0.001). Need for PPM was correlated to the depth of prosthesis implantation (r = 0.590; P = 0.001). At a cutoff point of 10.1 mm, the likelihood of pacemaker could be predicted with 87.5% sensitivity and 74% specificity and a receiver operator characteristic curve area of 0.86 ± 0.07 (P = 0.003). Of the seven patients with preexisting right bundle branch block (RBBB), four (57.1%) required PPM implantation after TAVI. Conclusions: High‐grade AV block requiring PPM implantation is a common complication following TAVI and could be predicted by a deeper implantation of the prosthesis. Patients with preexisting RBBB also seem to be at risk for the development of high‐grade AV block and subsequent pacemaker implantation. (PACE 2010; 1364–1372)     

Unexpected, dramatic improvement in atrioventricular conduction during pacemaker implantation for apparent complete heart block

We describe the case of a 29-year-old man with complete heart block after aortic and mitral valve surgery for bacterial endocarditis. Prior to pacemaker implantation, the patient had sinus bradycardia with third degree atrioventricular (AV) block. During testing of the atrial lead, the patient manifested intact AV conduction with a constant PR interval, which was robust up to 120 beats/min. This case represents a dramatic example of unexpected, improved AV conduction, perhaps a result of loss of Phase IV block.     

TAVR术后传导阻滞及起搏器植入的预测因子研究进展

主动脉瓣狭窄(AS)是由先天或后天因素所引起的瓣膜结构改变,其发病率随着年龄的增长而增加,在80岁以上人群中患病率可达到10%左右,其中严重主动脉瓣狭窄导致的猝死每年发生率约为 1%[1]。经导管主动瓣膜置换术 (TAVR)是一种安全可行的重度AS微创治疗方法,自2011年FDA首次获批应用于无法进行外科手术治疗的重度AS患者,其适应症不断拓展至中低手术风险人群的治疗。人工瓣膜的置入压迫位于主动脉根部的房室传导系统,导致术后心脏传导异常的发生,永久起搏器的植入(PPMI)是其治疗手段。TAVR术后PPMI与患者预后密切相关。因此,本文对TAVR术后传导功能障碍发生及PPMI进行综述。     

Long-term mortality and pacing outcomes of patients with permanent pacemaker implantation after cardiac surgery

Background: Approximately 20,000 permanent pacemakers (PPMs) are implanted annually for bradycardia or atrioventricular (AV) block after cardiac surgery. Little is known about the long‐term pacing and mortality outcomes and the temporal trends of these patients. Methods: We examined 6,268 consecutive patients who underwent cardiac surgery at the Minneapolis Veterans Administration Medical Center between 1987 and 2010. Patients who had a PPM within 30 days of cardiac surgery were identified. Pacemaker interrogation records were retrospectively reviewed and mortality was ascertained. Results: Overall, 141 (2.2%) patients underwent PPM implantation for high‐degree AV block (55%) and bradycardia (45%), 9 ± 6 days after surgery. Age, diuretic use, cardiopulmonary bypass time (CPBT), and valve surgery were independent predictors of PPM requirement. After 5.6 ± 4.2 years of follow‐up, 40% of the patients were PPM dependent. Longer CPBT (P = 0.03), PR interval >200 ms (P = 0.03), and QRS interval > 120 ms (P = 0.04) on baseline electrocardiogram predicted PPM dependency . In univariable analysis, PPM patients had a higher long‐term mortality than those without PPM (45% vs 36%; P = 0.02). However, after adjusting for age, sex, type of surgery, and CPBT, PPM requirement was not associated with long‐term mortality (hazard ratio 1.3; 95% confidence interval 0.9–1.9; P = 0.17). Compared to before, incidence of PPM implantation increased after the year 2000 (1.9% vs 2.6%; P = 0.04). Conclusion: The majority of patients who require PPM after cardiac surgery are not PPM dependent in the long term. Requiring a PPM after surgery is not associated with long‐term mortality after adjustment for patient‐related risk factors and cardiac surgical procedure. (PACE 2011; 34:331–338)     

Atrioventricular Conduction Abnormalities in Patients Undergoing Isolated Aortic or Mitral Valve Replacement

Cardiac conduction defects are common in patients with aortic valve disease. Several studies have suggested that the spontaneous occurrence of complete heart block in these patients is related to the extent of calcium deposits in the aortic valve and adjacent structures. No studies have been done to relate the occurrence of complete heart block at the time of valve replacement to predictive factors. We evaluated 102 consecutive patients undergoing isolated aortic valve replacement and 100 patients undergoing isolated mitral valve replacement. Although transient complete heart block was relatively common in each group (17.6% and 13%, respectively), we were not able to identify any factors predictive of its occurrence. There was a very low incidence of late heart block in a follow-up period of over four years. Thus, the capability for temporary pacing is mandatory in patients undergoing volve replacement. However, transient complete AV block during the perioperative period does not predict late recurrence of AV block and, therefore, prophylactic pacemaker or electrode implantation during or following transient block appears unnecessary.     

Imaging‐based predictors of permanent pacemaker implantation after transcatheter aortic valve replacement

1 Background

Cardiac conduction abnormalities requiring permanent pacemaker (PPM) implantation are major complications of transcatheter aortic valve replacement (TAVR). We aimed to investigate whether the relationship between prosthetic valve size and cardiac‐gated computed tomography (CT)‐based aortic root complex measurements can aid in recognizing patients at risk for PPM implantation post‐TAVR.

2 Methods

We included 83 of 114 consecutive patients who underwent TAVR with the Edwards Sapien valve (Edwards Lifesciences, Irving, CA, USA) at our institution. We excluded patients with preexisting PPM, patients who required conversion to an open surgical procedure, and patients without CT data. We assessed the significance of various potential predictors of PPM placement post‐TAVR.

3 Results

Following TAVR, eight patients (9.6%) required PPM. Prosthetic valve to sinus of Valsalva (SOV) index was significantly higher in those patients requiring a PPM post‐TAVR (84.1 ± 9.3 vs 76.8 ± 7.1, P  =  0.009).

4 Conclusions

The prosthetic valve size to diameter of SOV index was identified as a novel predictor of PPM implantation after TAVR.     

Transcatheter aortic valve replacement and cardiac conduction

Introduction: Conduction abnormalities after transcatheter aortic valve replacement (TAVR) account for a high percentage of post-TAVR complications.

Areas covered: The etiology of conduction abnormalities is closely tied to cardiac anatomy (length of membranous septum, degree of calcification, location of left bundle within the membranous septum), baseline conduction abnormalities (preprocedure right bundle branch block), and procedural variables (type of valve, depth of implant). Management of new high-grade AV block and new left bundle branch block varies by institution in the absence of consensus guidelines.

Expert opinion: Authors describe the incidence, etiology, outcomes, and management of conduction abnormalities related to aortic stenosis and TAVR.     

Inadvertent pacemaker lead dislodgement

Transcatheter aortic valve implantation (TAVI) has become an established treatment option for aortic valve stenosis in patients with a high risk for conventional surgical valve replacement. A well‐known complication is the development of conduction abnormalities. In the case of a new third‐degree atrioventricular block, the complication can be life‐threatening and permanent pacing is needed. Often these patients have a venous sheath placed in the jugular vein for the perioperative period. We report a case of inadvertent dislodgement of a permanent pacemaker lead after removal of a preoperatively placed venous sheath in a TAVI patient.     

Atrioventricular Conduction Disturbances in Patients with Sinoatrial Node Disease and Atrial Pacing

In sinoatrial node disease (SND) atrial pacing may be limited by progression of AV block. The incidence of AV block after All systems implantation range, according to various authors, from 0% to 12%. The aim of this study was to examine the AV conduction disturbances that forced a change in the mode of pacing in patients with AAI pacemakers. The information was collected retrospectively from a cohort of 122 patients. The follow-up period ranged from 5 to 83 months (mean = 35J. Among these patients there were 37 with sinus bradycardia and 85 with bradycardia-tachycardia syndrome. Their mean age was 63 years. Before AAI pacemaker insertion, all patients had normal AV conduction on 12-lead EGG, and all but five had a Wenckebach cycle length shorter than 500 msec. Seven out of these 122 patients (5.7%) developed symptomatic conduction disturbances (second-degree type I AV block in five, second degree type II AV block in one, and third-degree AV block in one], necessitating a change from AAI to another mode of pacing. We conclude that progression of AV block after atrial pacemaker implantation in patients with SND is infrequent and mild in the majority of cases. Intraventricular disturbances such as left anterior hemiblock represent contraindication to AAI pacing particularly in patients who may be in need of antiarrhythmic drugs.     

Early regression of left ventricular hypertrophy after aortic valve replacement by the Ross procedure detected by cine MRI.

AIM: The primary objective of our study was to assess the time course of left ventricular remodeling after the Ross procedure with the use of cine magnetic resonance imaging (MRI). METHODS: In a prospective study, 10 patients with isolated aortic valve disease were examined prior to aortic valve surgery, as well as at early follow-up (mean 4 weeks) and at late follow-up (mean 8 months) after pulmonary autograft aortic valve replacement (Ross procedure). The heart was imaged with a 1.5 T MR scanner along the short and long axes using a breath-hold, electrocardiogram (ECG)-triggered, cine gradient-echo sequence (FLASH). Myocardial mass and ventricular function were assessed. RESULTS: After aortic valve replacement, left ventricular myocardial mass (LVM) decreased by 13% (261 +/- 74 g to 230 +/- 65 g, p < 0.05) in the early postoperative period and by a further 16% in the late postoperative period to 192 +/- 31 g (p < 0.05). In addition, left ventricular end-diastolic and end-systolic volumes decreased from preoperative 187 +/- 89 mL (LV EDV) and 73 +/- 59 mL (LV ESV) to 119 +/- 55 mL and 56 +/- 42 mL, respectively, in the early postoperative period. In the late postoperative period, there was a further decrease to 98 +/- 30 (p < 0.05) and 33 +/- 19 mL, respectively. Ejection fraction did not change markedly after surgery (preoperatively 61 +/- 13% vs. 56 +/- 14% postoperatively). Patients with leading aortic stenosis were characterized by predominant regression of LVM and patients with leading aortic regurgitation by predominant regression of LV EDV (each p < 0.05). CONCLUSION: Cine MRI allows accurate assessment of left ventricular structure and geometry before and after aortic valve replacement with pulmonary autograft and is very sensitive in detecting relatively small changes of left ventricular myocardial mass and volumes early after hemodynamic relief as well as during serial assessment.     

Surface and intracardiac ECG for discriminating conduction disorders after CoreValve implantation

Background

Transcatheter aortic valve implantation (TAVI) has been developed to minimize operative morbidity and mortality in high-risk symptomatic patients unfit for open surgery. With the proximity of the aortic valve annulus to the conduction system there is, however, an unknown risk of conduction disturbances necessitating monitoring and often cardiac pacing.

Materials and methods

We enrolled 50 consecutive patients from January 2007 to 2008 in our prospective evaluation of conduction disturbances measured by surface and intracardiac ECG recordings. Baseline parameters, procedural characteristics as well as twelve-lead surface ECG and intracardiac conduction times were revealed pre-interventionally, after TAVI and at 7-day follow-up.

Results

TAVI was performed successfully in all patients. During 7?days of follow-up the rate for first-degree AV block raised from 14% at baseline to 44% at day 7 (p?p?p?p?p?p?Conclusion Cardiac conduction disturbances were common in the early experience with CoreValve implantation necessitating close surveillance for at least 1?week.     

Sutureless aortic valves over the last 45 years

Degenerative and calcified aortic stenosis is the most common form of adult valvular heart disease, and surgical aortic valve replacement (AVR) with the use of extracorporeal circulation (ECC) is currently the method of choice which can be performed at low risk. However, older patients with multiple pre-existing ‘high-risk’ comorbid conditions may benefit from reduced ECC time and thus reduced myocardial ischemia by the use of minimally invasive or interventional aortic valve implantation. Therefore, a sutureless concept of aortic valve implantation came up in the early sixties. However, this innovative concept of sutureless heart valve implantation was abandoned again due to several disadvantages. To date, there is a growing need for fast sutureless implantation of valve prostheses due to an increase in comorbidities. New challenging fields in aortic valve surgery have been recently rediscovered followed by an improvement of the sutureless valve implantation technique. Therefore, we reviewed the current and historical literature describing valve design and materials, as well as clinical data based on valve-related complications or morbidity/mortality.     

Pacemaker Dependency After Coronary Artery Bypass

A retrospective study was carried out on 36 patients (33 males and 3 females) to determine the incidence of WI pacemaker dependency following coronary artery bypass surgery. Pacemaker dependency was defined as the presence of pacemaker activity when pacing rate was programmed at 50 beats/min and/or when no hemodynamic adequate rhythm was present during pulse generator replacement. The patients were divided into two groups: (group I) 26 patients with complete atrioventricular (AV) block developing in the early postoperative period. In most of them a pacemaker was implanted up to 3 weeks following surgery (range 2 days to 1 year); (group II) ten patients in whom the indication for pacemaker implantation was sick sinus syndrome with sinus arrest and/or tachy-bradycardia. These patients underwent pacemaker implantation at varying periods of time following surgery (range 12 days to 4 years). Unipolar endocardial leads with VVI programmable pacemakers were implanted in all patients included in this study. Mean follow-up time was 3 years. In group I the pacemaker dependency rate was 65%, whereas in group II it was 30% throughout the follow-up period. It is concluded that the low incidence of pacemaker dependency in patients who undergo pacemaker implantation after coronary bypass surgery necessitates frequent evaluation in the nondependent patient, in order to reassess the need for the pacemaker before pulse generator replacement. Such reassessment should probably include prolonged ambulatory monitoring as well as invasive evaluation of the conduction system, if avoidance of pulse generator replacement is considered.     

Subacute aortic prosthetic mechanical valve thrombosis complicated with acute coronary syndrome

A prosthetic valve thrombosis (PVT), which is a potentially fatal complication, refers to the presence of non-infective thrombotic material on a prosthetic valve apparatus, interfering with its function. Possible complications of a PVT include transient neurologic embolic events, cardiac arrest due to a stuck valve prosthesis, and cardio-embolic myocardial infarction (MI). The choice of treatments, including a redo surgery, a percutaneous coronary intervention (PCI), and a fibrinolysis with PVT or MI dosages, depends on the patient's clinical and hemodynamic status and thrombotic burden involving the prosthetic valve and surrounding tissues. An early postoperative mechanical valve thrombosis is associated with increased risks due to the need for unforeseen early redo surgery complications and excessive bleeding risk in case of thrombolytic therapy usage. Here, we present a fifty-seven-year old female patient who was admitted to the emergency department with the complaint of acute chest pain seven days after an aortic prosthetic mechanical valve implantation. The clinical presentation was consistent with ST segment elevated MI and echocardiography revealed a large mass on the recently implanted prosthetic aortic valve. Valvular thrombotic complications after heart valve replacement operations are associated with high morbidity and mortality rates. Efficient and urgent treatment is necessary. Considering the clinical status of the patient, we preferred fibrinolytic therapy rather than PCI or surgery. The aim of this case report was to show the efficiency and safety of low-dose slow-infusion fibrinolytic therapy in PVT complicated with acute coronary syndrome.     

Prosthesis-patient mismatch after transcatheter aortic valve implantation: impact of 2D-transthoracic echocardiography versus 3D-transesophageal echocardiography

To investigate the role of 2D-transthoracic echocardiography (2D-TTE) and 3D-transesophageal echocardiography (3D-TEE) in the determination of aortic annulus size prior transcatheter aortic valve implantation (TAVI) and its’ impact on the prevalence of patient prosthesis mismatch (PPM). Echocardiography plays an important role in measuring aortic annulus dimension in patients undergoing TAVI. This has great importance since it determines both eligibility for TAVI and selection of prosthesis type and size, and can be potentially important in preventing an inadequate ratio between the prosthetic valvular orifice and the patient’s body surface area, concept known as prosthesis-patient mismatch (PPM). A total of 45 patients were studied pre-TAVI: 20 underwent 3D-TEE (men/women 12/8, age 84.8 ± 5.6) and 25 2D-TTE (men/women 9/16, age 84.4 ± 5.4) in order to measure aortic annulus diameter. The presence of PPM was assessed before hospital discharge and after a mean period of 3 months. Moderate PPM was defined as indexed aortic valve area (AVAi) ≤ 0.85 cm²/m² and severe PPM as AVAi < 0.65 cm²/m². Immediately post-TAVI, moderate PPM was present in 25 and 28 % of patients worked up using 3D-TEE and 2D-TTE respectively p value = n.s) and severe PPM occurred in 10 % of the patients who underwent 3D-TEE and in 20 % in those with 2D-TTE (p value = n.s). The echocardiographic evaluation 3 months post-TAVI showed 25 % moderate PPM in the 3D-TEE group compared with 24 % in the 2D-TTE group (p value = n.s) and no cases of severe PPM in the 3DTEE group comparing to 20 % in the 2D-TTE group (p = 0.032). Our results indicate a higher incidence of severe PPM in patients who performed 2DTTE compared to those performing 3DTEE prior TAVI. This suggests that the 3D technique should replace the 2DTTE analysis when investigating the aortic annulus diameter in patients undergoing TAVI.     

Small balloon strategy associated with low pacemaker implantation rate after self-expanding transcatheter valve implantation

BACKGROUND: This study aims to investigate whether small balloon aortic valvuloplasty(BAV) reduces the need for permanent pacemaker implantation (PPMI) after transcatheter aortic valveimplantation (TAVI).METHODS: This was a retrospective analysis using data from our local TAVI database. SmallBAV was defined as a small balloon size (=18 mm) pre-dilatation. Normal BAV was defined as aballoon size >18 mm. The primary endpoint was the incidence of new PPMI.RESULTS: Of 99 consecutive TAVI patients, five patients were excluded due to pre-existingpermanent pacemaker. Patients in the small BAV group (n=57) had a signifi cantly lower PPMI ratecompared with the normal BAV group (n=37) (3.5% vs. 18.9%, P=0.026). Moderate or severe aorticvalve regurgitation post-procedure was similar between the small BAV and normal BAV groups (5.3%vs. 8.1%, P=0.480);likewise, the mean aortic gradient post-procedure did not differ significantly(11.5±5.2 mmHg vs. 12.2±7.3 mmHg, 1 mmHg=0.133 kPa, P=0.580) between the groups. Devicesuccess rates were also similar (94.7% vs. 91.8%, P=0.680). In multivariable analysis, small BAV(P=0.027), the ratio of prosthesis diameter to annulus diameter (P=0.048), and mean aortic gradientby echo in the basement (P=0.021) were independent predictors of PPMI.CONCLUSIONS: The small BAV strategy is associated with a low rate of permanentpacemaker implantation after transcatheter self-expanding valve implantation in this single-centerobservational study.     

超声心动图评估主动脉瓣置换术后早期并发症的临床应用

主动脉瓣置换术(AVR)是目前治疗有症状的主动脉瓣病变的标准手术。AVR可明显改善主动脉瓣狭窄或反流患者的临床症状及血流动力学,手术效果好,远期生存率高。尽管经导管主动脉瓣置入术(TAVI)也被认可为治疗主动脉瓣病变的有效手段,但目前AVR仍然是最可靠的手术方式。超声心动图是主动脉瓣狭窄或反流最重要的诊断方法,是一种安全可靠的无创检测技术,在术前评估、明确手术指证、选择手术方式、判断预后等方面有重要的价值。AVR术后30d内发生的早期并发症影响患者预后,目前主要依靠超声心动图来检测和诊断。常规超声心动图的应用最为广泛,近年来超声心动图新技术如组织多普勒显像(TDI)、二维或三维斑点追踪显像、负荷超声心动图的应用也得到越来越多的临床医师重视。然而,超声心动图对AVR术后早期并发症的预测价值尚无充分的证据证明。笔者对AVR术后主要早期并发症及超声心动图检测方法进行系统回顾,以期为探究超声心动图指标预测术后早期并发症的价值提供参考。     

阵发性完全性房室传导阻滞致心源性晕厥50例临床研究

目的通过对50例阵发性完全性房室传导阻滞所致心源性晕厥的资料进行分析,总结其临床及心电图特点。方法收集2001年1月至2014年1月50例诊断为阵发性完全性房室传导阻滞致心源性晕厥患者入院资料,包括一般临床资料、心电图、超声心动图、X线胸片、24 h动态心电图及心内电生理检查等。分析其资料特点。结果 50例患者中,20例伴有缺血性心脏疾病,18例房室传导阻滞患者服用β受体阻滞剂,12例患者在急性心肌梗死恢复过程中发生完全性房室传导阻滞,3例发生在慢性头痛过程中,5例发生在主动脉瓣置换术后。所有患者的发生时间从2.2~15 s不等。16例患者的心电图显示宽QRS波形。及时的处理措施包括静脉补液及阿托品注射、停服β受体阻滞剂、植入临时心脏起搏器等。结论完全性阵发性房室传导阻滞与迷走神经反应、影响房室传导药物和传导系统疾病有关,大多数患者最终需要植入永久性心脏起搏器。