Sinus node dysfunction and stroke risk: a systematic review and meta-analysis.

OBJECTIVES: The role of cardiac arrhythmia in ischaemic stroke is widely studied, but the size of the stroke risk in patients with sinus node dysfunction (SND) with and without atrial fibrillation (AF) is unclear. This systematic review and meta-analysis aimed to compare the risk of stroke and its associated factors in patients with SND with and without AF. DESIGN: A systematic review and meta-analysis was conducted based on the Grading of Recommendations, Assessment, Development and Evaluation approach. DATA SOURCES: PubMed, EMBASE and Cochrane Database were searched until December 2022. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Studies that investigate stroke in patients with SND diagnosed with or without AF/atrial flutter. DATA EXTRACTION AND SYNTHESIS: Two independent authors screened studies for inclusion and extracted data. Literature quality assessment was performed using the Newcastle-Ottawa Scale and the Cochrane Collaboration Tool. The overall risk of stroke was estimated using the random-effects model. The generic inverse variance method was used to calculate the pooled estimates of stroke-associated factors. We performed a sensitivity analysis using a fixed-effects model. RESULTS: Of the 929 records retrieved, 6 papers (106 163 patients) met the inclusion criteria. The average yearly stroke incidence in patients with SND was 1.542% (95% CI: 1.334% to 1.749%). The stroke incidence was similar between the isolated SND (1.587%; 95% CI: 1.510% to 1.664%) and non-isolated (SND+AF) (1.660%; 95% CI: 0.705% to 2.615%) groups. AF (HR, 95% CI: 1.53 (1.01 to 2.33)), stroke/transient ischaemia attack/other thrombotic events (HR, 95% CI: 2.54 (1.14 to 5.69)), hypertension (HR, 95% CI: 1.51 (1.11 to 2.07)) and heart failure (HR, 95% CI: 1.41 (1.01 to 1.97)) were associated with stroke in the SND population. CONCLUSION: Our findings suggest that patients with SND carry a similar risk of stroke to those with combined SND and AF. Future studies are needed to investigate whether interventions targeting stroke prevention, such as anticoagulation therapy, can help to prevent stroke in patients with SND. PROSPERO REGISTRATION NUMBER: CRD42023408436.

Incidence and predictors of pacemaker implantation at follow-up after reversible high-degree sinus node dysfunction or atrioventricular block.

BACKGROUND: A pacemaker implantation is not indicated in cases of reversible high-degree symptomatic sinus node dysfunction (SND) and atrioventricular block (AVB). However, it remains uncertain whether these reversible automaticity/conduction disorders may recur in some patients at follow-up, in the absence of reversible cause. This retrospective study aimed to determine the incidence and predictive factors of permanent pacemaker (PPM) implantation at follow-up and after reversible high-degree SND/AVB. METHODS: Based on medical electronic files codes, we identified patients who were hospitalized in our cardiac intensive care unit between January 2003 and December 2020 due to reversible high-degree SND/AVB and who were discharged from the hospital alive and without PPM implantation. Acute myocardial infarction and post-cardiac surgery patients were excluded. We categorized the patients according to the need for PPM at follow-up due to non-reversible high-degree SND/AVB. RESULTS: Of the 93 patients included, 26 patients (28%) were readmitted for PPM implantation at follow-up after hospital discharge. Among baseline characteristics, compared with patients who did not have high-degree SND/AVB recurrence, those who had subsequent PPM implantation had less frequent previous hypertension (70% vs. 46%, p = .031). Regarding the initial causes of reversible SND/AVB, isolated hyperkalemia was found more often in the patients readmitted for PPM (19% vs. 3% vs. p = .017). Moreover, recurrence of high-degree SND/AVB was significantly associated with the presence of intraventricular conduction disorders (either bundle branch block or left bundle branch hemiblock) on ECG at discharge (36% in patients without PPM vs. 68% in PPM patients, p = .012). CONCLUSION: Almost one third of the patients discharged alive from the hospital after a reversible high-degree SND/AVB needed a pacemaker implantation at follow-up. Complete bundle branch block or left bundle branch hemiblock on discharge ECG after recovery of atrioventricular conduction and/or sinus automaticity was associated with a greater risk of recurrence leading to pacemaker implantation.

Association between sick sinus syndrome and atrial fibrillation: A systematic review and meta-analysis.

AIMS: Sick sinus syndrome (SSS) and atrial fibrillation (AF) frequently coexist and show a bidirectional relationship. This systematic review and meta-analysis aimed to decipher the precise relationship between SSS and AF, further exploring and comparing different therapy strategies on the occurrence or progression of AF in patients with SSS. METHODS AND RESULTS: A systematic literature search was conducted until November 2022. A total of 35 articles with 37,550 patients were included. Patients with SSS were associated with new-onset AF compared to those without SSS. Catheter ablation was associated with a lower risk of AF recurrence, AF progression, all-cause mortality, stroke and hospitalization of heart failure compared to pacemaker therapy. Regarding the different pacing strategies for SSS, VVI/VVIR has higher risk of new-onset AF than DDD/DDDR. No significant difference was found between AAI/AAIR and DDD/DDDR, as well as between DDD/DDDR and minimal ventricular pacing (MVP) for AF recurrence. AAI/AAIR was associated with higher risk of all-cause mortality when compared to DDD/DDDR, but lower risk of cardiac death when compared to DDD/DDDR. Right atrial septum pacing was associated with a similar risk of new-onset AF or AF recurrence compared to right atrial appendage pacing. CONCLUSION: SSS is associated with a higher risk of AF. For patients with both SSS and AF, catheter ablation should be considered. This meta-analysis re-emphasizes that high percentage of ventricular pacing should be avoided in patients with SSS in order to decrease AF burden and mortality.

Screening of Fabry disease in patients with an implanted permanent pacemaker.

BACKGROUND: Anderson-Fabry disease (AFD) is an X-linked inherited lysosomal disease caused by a defect in the gene encoding lysosomal enzyme α-galactosidase A (GLA). Atrio-ventricular (AV) nodal conduction defects and sinus node dysfunction are common complications of the disease. It is not fully elucidated how frequently AFD is responsible for acquired AV block or sinus node dysfunction and if some AFD patients could manifest primarily with spontaneous bradycardia in general population. The purpose of study was to evaluate the prevalence of AFD in male patients with implanted permanent pacemaker (PM). METHODS: The prospective multicentric screening in consecutive male patients between 35 and 65 years with implanted PM for acquired third- or second- degree type 2 AV block or symptomatic second- degree type 1 AV block or sinus node dysfunction was performed. RESULTS: A total of 484 patients (mean age 54 ± 12 years at time of PM implantation) were enrolled to the screening in 12 local sites in Czech Republic. Out of all patients, negative result was found in 481 (99%) subjects. In 3 cases, a GLA variant was found, classified as benign: p.Asp313Tyr, p.D313Y). Pathogenic GLA variants (classical or non-classical form) or variants of unclear significance were not detected. CONCLUSION: The prevalence of pathogenic variants causing AFD in a general population sample with implanted permanent PM for AV conduction defects or sinus node dysfunction seems to be low. Our findings do not advocate a routine screening for AFD in all adult males with clinically significant bradycardia.

Implantation of cardiac electronic devices in active COVID-19 patients: Results from an international survey.

BACKGROUND: Cardiac implantable electronic device (CIED) implantation rates as well as the clinical and procedural characteristics and outcomes in patients with known active coronavirus disease 2019 (COVID-19) are unknown. OBJECTIVE: The purpose of this study was to gather information regarding CIED procedures during active COVID-19, performed with personal protective equipment, based on an international survey. METHODS: Fifty-three centers from 13 countries across 4 continents provided information on 166 patients with known active COVID-19 who underwent a CIED procedure. RESULTS: The CIED procedure rate in 133,655 hospitalized COVID-19 patients ranged from 0 to 16.2 per 1000 patients (P <.001). Most devices were implanted due to high-degree/complete atrioventricular block (112 [67.5%]) or sick sinus syndrome (31 [18.7%]). Of the 166 patients in the study survey, the 30-day complication rate was 13.9% and the 180-day mortality rate was 9.6%. One patient had a fatal outcome as a direct result of the procedure. Differences in patient and procedural characteristics and outcomes were found between Europe and North America. An older population (76.6 vs 66 years; P <.001) with a nonsignificant higher complication rate (16.5% vs 7.7%; P = .2) was observed in Europe vs North America, whereas higher rates of critically ill patients (33.3% vs 3.3%; P <.001) and mortality (26.9% vs 5%; P = .002) were observed in North America vs Europe. CONCLUSION: CIED procedure rates during known active COVID-19 disease varied greatly, from 0 to 16.2 per 1000 hospitalized COVID-19 patients worldwide. Patients with active COVID-19 infection who underwent CIED implantation had high complication and mortality rates. Operators should take these risks into consideration before proceeding with CIED implantation in active COVID-19 patients.

Risk of sick sinus syndrome in patients diagnosed with atrial fibrillation: A population-based cohort.

BACKGROUND: Sinoatrial node dysfunction and atrial fibrillation (AF) frequently coexist and interact with each other, often to initiate and perpetuate each other. OBJECTIVE: To determine the effect of AF on the incidence and risk of sick sinus syndrome (SSS). METHODS: The association of incident AF with the development of incident SSS was assessed from 2004 to 2014 in 302 229 SSS- and pacemaker-free subjects aged ≥60 years in the Korea National Health Insurance Service-Senior cohort. RESULTS: During an observation period of 1 854 800 person-years, incident AF was observed in a total of 12 797 subjects (0.69%/year). The incidence of SSS was 3.4 and 0.2 per 1000 person-years in the propensity score-matched incident AF and no-AF groups, respectively. After adjustment, the significantly increased risk of SSS was observed in the incident AF group, with a hazard ratio (HR) of 13.4 (95% confidence interval [CI]: 8.4-21.4). This finding was consistently observed after censoring for heart failure (HR: 16.0; 95% CI: 9.2-28.0) or heart failure/myocardial infarction (HR: 16.6; 95% CI: 9.3-29.7). Incident AF also was associated with an increased risk of pacemaker implantation related with both SSS (HR: 21.8; 95% CI: 8.7-18.4) and atrioventricular (AV) block (HR: 9.5; 95% CI: 4.9-18.4). These results were consistent regardless of sex and comorbidities. CONCLUSION: Incident AF was associated with more than 10 times increased risk of SSS in an elderly population regardless of comorbidities. The risk of pacemaker implantations related with both sinus node dysfunction and AV block was increased in the elderly population with incident AF.

Impact of the atrial lead pacing site regarding atrial fibrillation onset in patients with sinus node dysfunction.

Symptomatic sinus node disease (SND) most frequently requires the implantation of a dual chamber pacemaker of which the right atrial lead is generally implanted in the right atrial appendage (RAA) or the lateral wall (LW).The aim of this retrospective study was to evaluate the impact of the right atrial lead pacing site regarding the onset of AF in patients with SND. RESULTS: 126 patients were included (53% males; 76 yo). 64 (51%) patients were implanted in the RAA and 62 (49%) in the LW. The two groups were not different in terms of CHA2DS2-VASc score and indexed left atrial volume. Forty-eight months after implantation, AF occurred in 17 (26.6%) of the RAA group and 6 (9.7%) in the lateral group. In the multivariate models, RAA site was the only factor associated with AF onset, with an Hazard Ratio of 2.5 (95%CI 1.1; 5.7; P=0.03). CONCLUSION: In our study, RAA pacing was associated with 2.5 higher risk of AF onset in patients with SND. Further larger randomized studies are needed to confirm these findings.

The risk factors of new-onset atrial fibrillation after pacemaker implantation.

OBJECTIVE: The aim of this study was to determine the incidence of newly detected atrial fibrillation (AF) in patients following dual-chamber pacemaker (PPM) implantation and to define the clinical predictors of new-onset AF in a Chinese cohort. METHODS: A total of 219 patients without documented AF that underwent dual-chamber PPM implantation for sick sinus syndrome (SSS) (n = 88) or atrioventricular block (AVB) (n = 131) were prospectively studied. All patients were invited to follow-up at 1 month, 3 months and 6 months after the pacemaker implantation procedure, and once every 6 months thereafter. An atrial high-rate episode (AHRE) ≥5 min and an atrial rate ≥180 bpm was defined as AF. RESULTS: During follow-up of 884 ± 180 days, AF was detected in 56 (26%) patients. Using Kaplan-Meier survival curves with Log-rank test, SSS patients with a cumulative percentage of ventricular pacing (Cum % VP) ≥60% had a significantly higher rate of new-onset AF compared to AVB patients (p = 0.026) and SSS patients with Cum % VP <60% (p = 0.018). On multivariate Cox regression analysis, higher Cum % VP independently predicted higher morbidity of newly detected AF (hazard ratio [HR] 1.01; confidence interval [CI] 1.00 ~ 1.02; p = 0.035) among SSS patients. Larger left atrial (LA) dimension was a predictor of newly detected AF (HR 1.06; CI 1.01 ~ 1.14; p = 0.046) in AVB patients. CONCLUSION: The incidence of AF following dual-chamber PPM implantation was relatively high in this Chinese cohort. High Cum % VP and larger LA dimension could independently predict new-onset AF after dual-chamber PPM implantation in SSS and AVB patients, respectively.

Prevalence, Incidence, and Impact on Mortality of Conduction System Disease in Transthyretin Cardiac Amyloidosis.

Transthyretin cardiac amyloidosis (ATTR-CA) is an increasingly recognized infiltrative cardiomyopathy in which conduction system disease is common. The aim of our study was to define the incidence and prevalence of high-grade atrioventricular (AV) block requiring pacemaker implantation in our quaternary referral center. This was a single-center retrospective cohort study of 369 consecutive patients with ATTR-CA who underwent 12-lead electrocardiogram at the time of ATTR-CA diagnosis. During a mean follow-up of 28 months, serial ECGs and the electronic medical record were examined for the development of high-grade AV block and pacemaker implantation. Wild-type ATTR-CA (wtATTR-CA) was diagnosed in 261 patients and 108 had hereditary ATTR-CA (hATTR-CA). A total of 35 (9.5%) had high-grade AV block requiring pacemaker implantation at the time of diagnosis of ATTR-CA. The most common conduction abnormalities evident on the baseline ECG were a wide QRS complex, present in 51% with wtATTR-CA and 48% with hATTR-CA (p = 0.62), followed by first-degree AV block, which was present in 49% with wtATTR-CA and 43% with hATTR-CA (p = 0.31). During follow-up, high-grade AV block developed in 10% of those with hATTR-CA and 12% of patients with wtATTR-CA (p = 0.64). On multivariable models, high-grade AV block was not significantly associated with increased mortality. More advanced ATTR-CA stage and a history of obstructive coronary artery disease were associated with increased mortality on multivariable models. In conclusion, the incidence and prevalence of high-grade AV block is high in patients with ATTR-CA. Patients with ATTR-CA require close monitoring during follow-up for the development of conduction system disease.

Ischemic Stroke in Patients With Sinus Node Disease, Atrial Fibrillation, and Other Cardiac Conditions.

Background and Purpose- Atrial fibrillation (AF) is known to increase risk of ischemic stroke (IS), but the risk of IS in isolated sinus node disease (SND) is unclear. We compared the incidence of IS in patients with SND, patients with AF, and in a control population with other cardiac diseases (disease of the circulatory system using the International Classification of Diseases, Tenth Revision). Methods- This French longitudinal cohort study was based on the national database covering hospital care for the entire population from 2008 to 2015. Results- Of 1 692 157 patients included in the cohort, 100 366 had isolated SND, 1 564 270 had isolated AF, and 27 521 had AF associated with SND. Incidence of IS during follow-up was higher in isolated patients with AF than in AF associated with SND (yearly rate 2.22% versus 2.06%) and in isolated patients with AF than in isolated patients with SND (yearly rate 2.22% versus 1.59%). The incidence of IS was lower in a control population with other cardiac conditions (n=479 108) compared with SND and patients with AF (0.96%/y, 1.59%/y, and 2.22%/y, respectively). After 1:1 propensity score matching, SND was associated with lower incidence of IS compared to AF (hazard ratio, 0.77 [95% CI, 0.73-0.82]) but higher incidence of IS compared to control population (hazard ratio, 1.27 [95%CI, 1.19-1.35]). Conclusions- Patients with SND had a lower risk of thromboembolic events than patients with AF but a higher risk than a control population with other cardiac diseases. Randomized clinical trial in a selected SND population, with, for example, a high CHA2DS2-VASc score, would be required to determine the value of IS prevention by anticoagulation.

Comparison of safety and outcomes with two approaches to the mitral valve.

BACKGROUND AND AIM: The efficacy of the superior trans-septal (STS) approach to the mitral valve has been offset by the perceived risks of adverse postoperative events. The aim of this study was to review our experience with using the left atriotomy (LA) and STS approaches in patients undergoing mitral valve surgery. METHODS: Charts of patients who underwent mitral valve surgery by a single surgeon over a period of 20 years were reviewed retrospectively. A total of 319 patients (aged 42.9 ± 16.2 years) were studied. Surgical operations were carried out through the LA approach in 111 patients, and through the STS approach in 208 patients. RESULTS: The two groups were comparable in terms of patients' characteristics, but cardiopulmonary bypass and aortic cross-clamp times were longer in the STS approach group (P = .0005). No technical complications related to either approach occurred. Rates of re-exploration for postoperative bleeding, durations of intensive care unit (ICU) stay, in-hospital days, and mortality were comparable in both approaches. Statistical analyses indicated that a patient was more likely to maintain a preoperative sinus rhythm if the LA approach rather than the STS approach was used (P < .05). On the other hand, when the preoperative heart rhythm was atrial fibrillation, no significant difference in perioperative changes in heart rhythm was observed between the two approaches. CONCLUSIONS: This study confirms that the routine use of the STS approach is not associated with important adverse postoperative outcomes, but is associated with increased incidence of postoperative sinus node dysfunction in patients who were in sinus rhythm preoperatively.

Immediate and long-term need for permanent cardiac pacing following aortic valve replacement.

Introduction: Atrioventricular (AV) node conduction disturbances are common following surgical aortic valve replacement (SAVR), and in some cases the patient needs a permanent pacemaker (PPM) implantation before discharge from hospital. Little is known about the long-term need for PPM and the PPM dependency of these individuals. We determined the incidence of PPM implantation before and after discharge in SAVR patients. Methods: We studied 557 consecutive patients who underwent SAVR for aortic stenosis in Iceland between 2002 and 2016. Timing and indication for PPM were registered, with a new concept, ventricular pacing proportion (VPP), defined as ventricular pacing ≥90% of the time, being used to approximate pacemaker dependency. The median follow-up time was 73 months. We plotted the cumulative incidence of pacemaker implantation, treating death as a competing risk. Results: Of the 557 patients, 22 (3.9%) received PPM in the first 30 days after surgery, most commonly for complete AV block (n = 14) or symptomatic bradycardia (n = 8); Thirty-eight other patients (6.8%) had a PPM implanted >30 days postoperatively, at a median of 43 months after surgery (range 0‒181), most often for AV block (n = 13) or sick-sinus syndrome (n = 10). The cumulative incidence of PPM implantation at 1, 5, and 10 years postoperatively was 5.0%, 9.2%, and 12.3%, respectively. During follow-up, 45.0% of the 60 patients had VPP ≥90%. Conclusion: The cumulative incidence of permanent pacemaker implantation following SAVR was about 12% at 10 years, with every other patient having VPP ≥90% during follow-up. This suggests that AV node conduction disturbances extend significantly beyond the perioperative period.

Registro Español de Marcapasos. XVI Informe Oficial de la Sección de Estimulación Cardiaca de la Sociedad Española de Cardiología (2018) / Spanish Pacemaker Registry. 16th Official Report of the Spanish Society of Cardiology Working Group on Cardiac Pacing (2018)

Introducción y objetivos: Se describe el resultado del análisis de los dispositivos de estimulación implantados y remitidos al Registro Español de Marcapasos en 2018. Métodos: Información que aporta la Tarjeta Europea del Paciente Portador de Marcapasos, así como los datos proporcionados por la industria sobre el número total de dispositivos implantados. Resultados: Se recibió información de 90 centros hospitalarios, con un total de 12.148 tarjetas, lo cual supone un 31% de la actividad total estimada. El consumo de generadores convencionales y de dispositivos de resincronización fue de 825 y 77 unidades por millón de habitantes respectivamente. La media de edad de los pacientes que recibieron un implante fue 78,3 años y un 54% de los dispositivos se implantaron en pacientes mayores de 80 años. El 77,1% de los procedimientos fueron primoimplantes y el 21,6%, recambios de generador. Aunque la estimulación secuencial bicameral sigue siendo mayoritaria, se utiliza menos en pacientes mayores de 80 años y en mujeres. Además, al 28% de los pacientes con enfermedad del nódulo sinusal y el 24,7% de aquellos con bloqueo auriculoventricular se los estimula en modo VVI/R pese a estar en ritmo sinusal. Conclusiones: El consumo total de generadores de marcapasos en España ha aumentado en un 1,2% con respecto al año 2017, fundamentalmente a expensas del aumento del consumo de generadores de terapia de resincronización cardiaca con marcapasos (8,7%). Los factores directamente relacionados con la elección del modo de estimulación son la edad y el sexo

Introduction and objectives: This report describes the result of the analysis of the implanted pacemakers reported to the Spanish Pacemaker Registry in 2018. Methods: The analysis is based on the information provided by the European Pacemaker Identification Card and supplier-reported data on the overall number of implanted pacemakers. Results: Information was received from 90 hospitals, with a total of 12 148 cards, representing 31% of the estimated activity. Use of conventional and resynchronization pacemakers was 825 and 77 units per million people, respectively. The mean age of the patients receiving an implant was 78.3 years, and 54% of the devices were implanted in people aged> 80 years. A total of 77.1% were first implants and 21.6% corresponded to generator exchanges. Bicameral sequential pacing was the most frequent pacing mode but was less frequently used in patients aged> 80 years and in women. Single chamber VVI/R pacing was used in 28% of patients with sick sinus syndrome and in 24.7% of those with atrioventricular block, despite being in sinus rhythm. Conclusions: The total consumption of pacemaker generators in Spain increased by 1.2% compared with 2017, mainly due to an 8.7% increase in cardiac resynchronization therapy with pacemaker generators. Selection of pacing mode was directly influenced by age and sex

Need for pacemaker implantation in patients with normal QRS duration immediately after transcatheter aortic valve implantation.

AIMS: We sought to assess the need for permanent pacemaker implantation (PPI) in patients with QRS <120 ms in electrocardiogram (ECG) after transcatheter aortic valve implantation (TAVI). METHODS AND RESULTS: We retrospectively analysed 1139 consecutive patients who underwent transfemoral TAVI between 2008 and 2016, receiving different valve types. All patients were surveyed by continuous ECG monitoring for 48 h, 12-lead ECGs starting immediately after procedure, as well as 24-h Holter recording the day before discharge. Indication for PPI was at the discretion of the attending physician. Among 760 patients with QRS <120 ms prior to the TAVI procedure, 400 patients showed QRS <120 ms immediately after procedure, whereas 360 patients had QRS ≥120 ms. In the group with QRS <120 ms, PPI was performed in 34 patients [8.5%; 95% confidence interval (CI) 5.6-11.2%] during the first week. Eight of the PPIs in the group with QRS <120 ms (2%; CI 0.8-3.5%) fulfilled Class I indications for PPI after TAVI, whereas 26 PPIs had different indications [left bundle branch block, sick sinus, low-grade atrioventricular (AV) block]. Complete AV block developed in three patients of the group of QRS <120 ms (0.75%; CI 0.0-1.7%), which in all cases occurred after the 48 h-surveillance period. During 1-year follow-up, 11 PPIs were performed (2.8%; CI 1.2-4.5%), thereof three PPI for Class I indications including one complete AV block. CONCLUSION: In patients with QRS duration <120 ms immediately after TAVI, the risk for complete AV block was low during the first week after TAVI and 1-year follow-up.

Prevalence and One-year Outcome of Carotid Sinus Hypersensitivity in Unexplained Syncope: A Prospective Cohort Study from South India.

BACKGROUND: Carotid sinus syndrome accounts for one third of patients who presents with unexplained syncope. Prevalence of carotid sinus hypersensitivity (CSH) in Indians has not been studied till now. OBJECTIVES: To assess the prevalence and associations of CSH in symptomatic patients above 50 years and to study its prognostic significance pertaining to sudden cardiac death, syncope, recurrent pre syncope and falls on 1 year follow up. METHODS: Patients above 50 years who presented with unexplained syncope, recurrent syncope or falls were considered cases and those without these symptoms were considered as controls. All the patients underwent carotid sinus massage and their responses noted. All symptomatic patients were followed up and observed for events like sudden cardiac death, syncope, recurrent pre syncope and falls during 1 year follow up. Patients with recurrent syncope and predominant cardioinhibitory syncope were advised permanent pacemaker implantation. RESULTS: A total of 252 patients were screened, 130 patients constituted cases and 49 patients constituted controls. CSH was demonstrable in 32% (n = 42) of cases as compared to 8% (n = 4) in controls (p < 0.001). Cardioinhibitory response was the predominant response (88%, n = 38) followed by mixed response (12%, n = 4). CSH was associated with advancing age, male gender (93%, n = 39, p < 0.001) and history of smoking (63%, n = 27, p = 0.009). Composite outcomes of sudden cardiac death, syncope, recurrent pre syncope and falls were significantly higher in patients with symptomatic CSH than in those without it (45%, n = 16 vs. 6.8%, n = 6; p < 0.001). CONCLUSIONS: In conclusion, the prevalence of CSH in patients above 50 yrs with unexplained syncope was high in our population. Patients with CSH and baseline symptoms developed recurrent syncope during follow up. Carotid sinus massage should be a part of routine examination protocol for unexplained syncope.

Pacemaker treatment after Fontan surgery-A Swedish national study.

OBJECTIVE: Fontan surgery is performed in children with univentricular heart defects. Previous data regarding permanent pacemaker implantation frequency and indications in Fontan patients are limited and conflicting. We examined the prevalence of and risk factors for pacemaker treatment in a consecutive national cohort of patients after Fontan surgery in Sweden. METHODS: We retrospectively reviewed all Swedish patients who underwent Fontan surgery from 1982 to 2017 (n = 599). RESULTS: After a mean follow-up of 12.2 years, 13% (78/599) of the patients with Fontan circulation had received pacemakers. Patients operated with the extracardiac conduit (EC) type of total cavopulmonary connection had a significantly lower prevalence of pacemaker implantation (6%) than patients with lateral tunnel (LT; 17%). Mortality did not differ between patients with (8%) and without pacemaker (5%). The most common pacemaker indication was sinus node dysfunction (SND) (64%). Pacemaker implantation due to SND was less common among patients with EC. Pacemaker implantation was significantly more common in patients with mitral atresia (MA; 44%), double outlet right ventricle (DORV; 24%) and double inlet left ventricle (DILV; 20%). In contrast, patients with pulmonary atresia with intact ventricular septum and hypoplastic left heart syndrome were significantly less likely to receive a pacemaker (3% and 6%, respectively). CONCLUSIONS: Thirteen percent of Fontan patients received a permanent pacemaker, most frequently due to SND. EC was associated with a significantly lower prevalence of pacemaker than LT. Permanent pacemaker was more common in patients with MA, DORV, and DILV.

Clinical features, predictors, and long-term prognosis of pacing-induced cardiomyopathy.

AIMS: We investigated the clinical features, predictors, and long-term prognosis of pacing-induced cardiomyopathy (PiCM). METHODS AND RESULTS: From a retrospective analysis of 1418 consecutive pacemaker patients, 618 were found to have a preserved baseline left ventricular ejection fraction (LVEF), follow-up echocardiographic data, and no history of heart failure (HF). PiCM was defined as a reduction in LVEF (< 50%) along with either (i) a ≥ 10% decrease in LVEF, or (ii) new-onset regional wall motion abnormality unrelated to coronary artery disease. PiCM occurred in 87 of 618 patients (14.1%), with a decrease in mean LVEF from 60.5% to 40.1%. The median time to PiCM was 4.7 years. Baseline left bundle branch block, wider paced QRS duration (≥ 155 ms), and higher ventricular pacing percentage (≥ 86%) were identified as independent predictors of PiCM in multivariate logistic regression analysis. The risk of PiCM increased gradually with the number of identified predictors, becoming more significant in the presence of two or more predictors (P < 0.001). During the entire follow-up (median 7.2 years), the risk of all-cause death or HF admission was significantly higher in patients with PiCM compared to those without PiCM (38.3% vs. 54.0%, adjusted hazard ratio 2.93; 95% confidence interval 1.82-4.72; P < 0.001). CONCLUSION: Pacing-induced cardiomyopathy patients showed a worse long-term prognosis than those without PiCM. Therefore, patients with multiple risk factors of PiCM should be monitored carefully even if their left ventricular systolic function is preserved initially. A timely upgrade to a biventricular or His-bundle pacing device needs to be considered in patients with PiCM.

Occurrence of significant long PR intervals in patients implanted for sinus node dysfunction and monitored with SafeR™: The PRECISE study.

BACKGROUND: Long PR intervals may increase cardiovascular complications, including atrial fibrillation. In pacemakers, the SafeR™ mode monitors PR intervals, switching from AAI to DDD when criteria for atrioventricular block are met. AIMS: The PRECISE study evaluated the incidence and predictors of long PR intervals and their association with incident atrial fibrillation after 1 year in patients implanted for sinus node dysfunction and free from significant conduction disorders at baseline. METHODS: This French, prospective, multicentre, observational trial enrolled patients implanted with a REPLY™ dual-chamber pacemaker. Pacemaker memory recorded long PR intervals (defined as first-degree atrioventricular block mode switches occurring after six consecutive PR/AR intervals≥350/450ms) and atrial fibrillation incidence (fallback mode switch>1minute/day). Predictors were identified from baseline variables (age, sex, AR and PR intervals, atrial rhythm disorder and medication) using logistic regression. RESULTS: Of 291 patients with sinus node dysfunction enrolled, 214 were free from significant conduction disorders at baseline (mean age 79±8 years; 44% men; PR/AR intervals<350/450ms). After 1 year, long PR intervals had occurred in 116 patients (54%) and atrial fibrillation in 63 patients (30%). Amiodarone was the only independent predictor of long PR interval occurrence (odds ratio 2.50, 95% confidence interval 1.20-5.21; P=0.014). There was a strong trend towards an association between long PR interval and atrial fibrillation incidence (odds ratio 1.86, 95% confidence interval 0.97-3.61; P=0.051). CONCLUSIONS: Half of the patients with pure sinus node dysfunction developed long PR intervals in the year following pacemaker implantation. Amiodarone was the only independent predictor of long PR intervals. There was a strong trend towards an association between long PR intervals and incident atrial fibrillation.

The incidence, indications and predictors of acute pacemaker implantation after ablation of persistent atrial fibrillation.

INTRODUCTION: Patients with persistent atrial fibrillation (AF) may additionally suffer from a concealed sinus node disease. We sought to determine the incidence, indications and predictors of acute pacemaker [PM] implantation within 1 week after the ablation of persistent AF. METHODS AND RESULTS: We performed a retrospective analysis of patients, who had had an ablation of persistent AF at our center. Between 01/2011 and 08/2016, 1234 patients (mean age 65 ± 10 years, 66.7% male) without prior PM implantation underwent an ablation of persistent AF. Pulmonary vein isolation (PVI) was performed in 1158 (93.8%), the additional ablation of complex fractionated atrial electrograms (CFAE) in 1109 (89.9%) and linear ablation in 524 (42.5%) patients. Temporary cardiac pacing was necessary in 27 (2.2%) patients. The temporary PM was removed in 15 patients (1.2%) because sinus node recovered after a median of 1.0 (minimum 0.1-maximum 2.0) day. The remaining 12 (1.0%) patients required the implantation of a permanent PM. Another 13 (1.1%) patients required permanent PM implantation without prior temporary pacing. In a multivariable regression model, age [OR 1.07 (1.02-1.12), p = 0.006], sinus pauses prior to ablation [OR 7.97 (2.36-26.88), p = 0.001] and atria with low voltage [OR 2.83 (1.31-6.11), p = 0.008] were identified as significant predictors for acute cardiac pacing. CONCLUSION: Acute cardiac pacing within 1 week after the ablation of persistent AF was necessary in 40 (3.2%) patients. Age, sinus pauses in history prior to ablation and the existence of low-voltage areas in the atria were identified as relevant risk factors.

Clinical characteristics and outcome of lone atrial fibrillation at a tertiary referral centre: the Groote Schuur Hospital experience.

INTRODUCTION: Atrial fibrillation (AF) is a relatively common arrhythmia. When AF represents an electrophysiological phenomenon in structurally normal hearts, it is termed lone AF. This study was a retrospective, case-based analysis of patients attending the Cardiac Clinic at Groote Schuur Hospital (GSH) and describes the clinical characteristics and outcomes of patients classified as having lone atrial fibrillation. To the best of our knowledge there are no such studies reported from Africa. METHODS: This was a retrospective, descriptive study in which 289 medical records of patients with AF at the GSH Cardiac Clinic were reviewed from 1992 to 2006. The clinical data were interrogated to exclude identifiable causes of AF. Information on clinical characteristics and outcomes were entered into a data-entry form. Baseline descriptive statistics were expressed as means and range for continuous variables, and counts with percentages for categorical variables. RESULTS: Fifteen per cent (n = 42) of patients were identified as having lone AF, with a mean follow-up time of 5.8 years. Males comprised 57% (n = 24) and females 43% (n = 18). Fifty per cent (n = 21) of the patients had paroxysmal AF, 29% (n = 12) had persistent AF, and 12% (n = 5) progressed from paroxysmal to permanent AF. Subsets of lone AF included concomitant atrial flutter (17%) (n = 7) and sick sinus syndrome (21%) (n = 9). Complications were stroke (10%) (n = 4), tachycardia-related cardiomyopathy (17%) (n = 7) and bleeding complications on warfarin (11%) (n = 3). CONCLUSIONS: Lone AF is not an uncommon arrhythmia, with a preponderance in thin, middle-aged males. The symptoms of lone AF can be debilitating. It has associated morbidity, including tachycardia-related cardiomyopathy and thromboembolism. Rate control and appropriate anticoagulation are the cornerstones of patient management.