Interventions in the diagnosis and adoption of pacemaker therapy in sinus node dysfunction patients: Results from the IMPROVE Brady study

Aims: IMPROVE Brady assessed whether a process improvement intervention could increase adoption of guideline-based therapy in sinus node dysfunction (SND) patients. Methods: /Results: IMPROVE Brady was a sequential, prospective, quality improvement initiative conducted in India and Bangladesh. Patients with symptomatic bradycardia were enrolled. In Phase I, physicians assessed and treated patients per standard care. Phase II began after implementing educational materials for physicians and patients. Primary objectives were to evaluate the impact of the intervention on SND diagnosis and pacemaker (PPM) implant. SF-12 quality of life (QoL) and Zarit burden surveys were collected pre- and post-PPM implant. A total of 978 patients were enrolled (57.7 ± 14.8 years, 75% male), 508 in Phase I and 470 in Phase II. The diagnosis of SND and implantation of PPM increased significantly from Phase I to Phase II (72% vs. 87%, P < 0.001 and 17% vs. 32%, P < 0.001, respectively). Pacemaker implantation was not feasible in 41% of patients due to insurance/cost barriers which was unaltered by the intervention. Both patient QoL and caregiver burden improved at 6-months post-PPM implant (P < 0.001). Conclusions: A process improvement initiative conducted at centers across India and Bangladesh significantly increased the diagnosis of SND and subsequent treatment with PPM therapy despite the socio-economic constraints.

Disfunción del nódulo sinusal asociado a estenosis severa proximal de la arteria coronaria derecha y vasoespasmo coronario

RESUMEN La disfunción del nódulo sinusal (DNS) es generalmente secundaria a la senescencia del nodo sinusal y del miocardio auricular circundante. Estamos presentando un paciente de 59 años de edad, hipertenso sin tratamiento y con antecedente de síncope en dos oportunidades en los últimos 4 meses. Ingresa debido a un flutter auricular con conducción auriculoventricular 1:1 con una frecuencia cardiaca de 280 lat/min que cede con goteo de amiodarona. Un Holter de 24 horas demostró un ritmo sinusal predominante, episodios paroxísticos de fibrilación auricular con respuesta ventricular alta, bradicardia sinusal de 47 lat/min. Se realizó el diagnóstico de disfunción del nódulo sinusal, Rubenstein tipo III (Síndrome Bradicardia-Taquicardia). Una coronariografía constató una estenosis del 80% en segmento proximal de la arteria coronaria derecha con componente espástico. La arteria del nódulo sinusal emerge del segmento proximal de la coronaria derecha. Se realizó una angioplastia exitosa con stent medicado. Otro estudio Holter de 24 horas de control pos-angioplastia registró nuevamente episodios paroxísticos de fibrilación auricular con respuesta ventricular alta y episodios de pausas de hasta 3.100 milisegundos por lo que se implantó un marcapasos bicameral. A pesar del restablecimiento de un flujo sanguíneo adecuado a la arteria del nódulo sinusal con la angioplastia de la coronaria derecha no se obtuvo una mejoría de la disfunción del nódulo sinusal.

ABSTRACT Sinus node dysfunction (SND) is generally secondary to senescence of the sinus node and the surrounding atrial myocardium. We are presenting a 59-year-old patient, hypertensive without treatment and with a history of syncope on two occasions in the last 4 months. He was admitted due to a 1: 1 atrioventricular conduction atrial flutter with a heart rate of 280 beats/min that subsides with an amiodarone drip. A 24-hour Holter monitor showed predominant sinus rhythm, paroxysmal episodes of atrial fibrillation with high ventricular response, sinus bradycardia of 47 beats/min. The diagnosis of sinus node dysfunction, Rubenstein type III (Bradycardia-Tachycardia Syndrome) was made. A coronary angiography confirmed an 80% stenosis in the proximal segment of the right coronary artery with a spastic component. The sinus node artery emerges from the proximal segment of the right coronary artery. A successful angioplasty was performed with a medicated stent. Another 24-hour Holter study of post-angioplasty control again recorded paroxysmal atrial fibrillation with high ventricular response episodes and pause episodes of up to 3,100 milliseconds, for which a dual-chamber pacemaker was implanted. Despite the restoration of adequate blood flow to the sinus node artery with right coronary angioplasty, no improvement in sinus node dysfunction was obtained.

Permanent Pacemaker Implantations after Catheter Ablation in Patients with Atrial Fibrillation Associated with Underlying Sinus Node Dysfunction

BACKGROUND AND OBJECTIVES: The objective of this study was to evaluate the long-term clinical outcomes and the incidence of permanent pacemaker implantation after catheter ablation in patients with of atrial fibrillation (AF) and sinus node dysfunction (SND).METHODS: Among 3,068 total consecutive patients who underwent AF catheter ablation (AFCA), this study included 222 (9.5%; men 53.2%, 63.7±9.2 years of age, 81.5% paroxysmal AF) with underlying SND and a regular rhythm follow-up. We analyzed the rhythm outcomes, changes in the mean heart rate or heart rate variability, and permanent pacemaker implantation rate.RESULTS: During 47.5±28.8 months of follow-up, 25 (11.3%) patients received pacemaker implantations due to symptomatic SND. More than half (56.0%, 14/25) underwent a pacemaker implantation within 3 months of the AFCA, and the annual pacemaker implantation rate was 2.0% afterwards. Both the early (68.0% vs. 31.0%, p<0.001) and clinical AF recurrence (68.0% vs. 32.5%, p=0.001) rates and continuous antiarrhythmic drug use after 3 months (44.0% vs. 24.4%, p=0.036) were significantly higher in patients requiring pacemaker implantations than those that did not. An anterior linear ablation (odds ratio [OR], 9.37 [3.03–28.9]; p<0.001) and the E/Em (OR, 1.15 [1.02–1.28]; p=0.018) were independently associated with permanent pacemaker implantations after AFCA in patients with AF and SND.CONCLUSIONS: After AFCA in patients with AF and SND, 1 of 9 patients needed a pacemaker implantation and half needed implantations within 3 months. The AF recurrence rate was significantly higher in those who required pacemaker implantations after the AFCA.

Diagnostic value of dynamic electrocardiogram combined esophageal electrophysiological examination ;for sick sinus syndrome / 心血管康复医学杂志

Objective:To explore diagnostic value of dynamic electrocardiogram (DCG) combined esophageal electro‐physiological examination (EEE) for sick sinus syndrome (SSS) .Methods :A total of 74 cases suspecting SSS ,who presented 24h mean heart rate <55 beats/min in DCG ,were selected .After DCG examination ,all subjects received EEE . Diagnostic value of single and combined examinations wereexplored .Results:Compared withthe SSS positive rate of single DCG and single EEE(87.8% ,86.5% ) ,theSSS positive rate ofDCG combined EEE(97.3% ) was sig‐nificantly rose ,P<0.05 both .Conclusion:Dynamic electrocardiogram combined esophageal electrophysiological ex‐amination can evaluate sinus node function from different angles ,which can significantlyincrease SSS diagnose rat .

Sinus Node Dysfunction with Pulmonary Edema Associated with Hyponatremia / 대한내과학회지

Hyponatremia is the most common electrolyte abnormality in hospitalized patients and often presents no symptoms. The association between sinus node dysfunction and hyponatremia has rarely been reported. We describe a 77-year-old woman who developed reversible sinus node dysfunction accompanied by pulmonary edema that was associated with hyponatremia.

Protective effects of kaempferol against cardiac sinus node dysfunction via CaMKII deoxidization / 대한해부학회지

Kaempferol exerts cardioprotective actions through incompletely understood mechanisms. This study investigated the molecular mechanisms underlying the cardioprotective effects of kaempferol in sinus node dysfunction (SND) heart. Here, we demonstrate that angiotensin II (Ang II) infusion causes SND through oxidized calmodulin kinase II (CaMKII). In contrast to this, kaempferol protects sinus node against Ang II-induced SND. Ang II evoked apoptosis with caspase-3 activation in sinus nodal cells. However, kaempferol lowered the CaMKII oxidization and the sinus nodal cell death. To block the CaMKII oxidization, gene of p47phox, a cytosolic subunit of NADPH oxidase, was deleted using Cas9 KO plasmid. In the absence of p47phox, sinus nodal cells were highly resistance to Ang II-induced apoptosis, suggesting that oxidized-CaMKII contributed to sinus nodal cell death. In Langendorff heart from Ang II infused mice, kaempferol preserved normal impulse formation at right atrium. These data suggested that kaempferol protects sinus node via inhibition of CaMKII oxidization and may be useful for preventing SND in high risk patients.

The comparison of catheter ablation and permanent pacing on patients with paroxysmal atrial fibrillation related tachycardia-bradycardia syndrome / 中国介入心脏病学杂志

Objective To evaluate the outcome of AF ablation in patients with paroxysmal atrial fibrillation (AF) related tachycardia-bradycardia syndrome. Methods Fifty consecutive patients with paroxysmal AF and prolonged symptomatic sinus pauses on termination of AF referred to our hospital for ablation were evaluated (ABL group). In another 61 patients, paroxysmal AF was treated with anti-arrhythmic drug and a pacemaker was implanted due to AF related tachycardia-bradycardia syndrome. These patients were used as control (PM group). Results A total of 50 patients in the ABL group fulfilled Class I indication for pacemaker implantation at baseline but they actually underwent AF ablation. Re-evaluation at the end of follow-up showed that 47 (94%) patients no longer needed a pacemaker (Class III indication) because of free from AF with no recurrences of pre-syncopal or syncopal events or documented sinus pauses after the last procedure. More patients in the PM group were on AADs (PM 42.6%, ABL 6.0%, P < 0.001) while sinus rhythm maintenance at the end of follow-up was remarkably higher in the ABL group (82.0%vs. 21.3%in PM group, P < 0.001). The total rates of cardiac related re-hospitalization was not significantly different between the two groups, but hospitalizations caused by tachyarrhythmia was significantly higher in the PM group (PM group 14.8%, ABL group 2.0%, P=0.020).The embolic events, heart failure and death rate were not significantly different between the two groups. Conclusions In patients with paroxysmal AF related tachycardia-bradycardia syndrome, AF ablation seems to be superior to a strategy of pacing plus AAD. Pacemaker implantation can be waived in the majority of patients after a successful ablation.

Long-Term Outcome of Single-Chamber Atrial Pacing Compared with Dual-Chamber Pacing in Patients with Sinus-Node Dysfunction and Intact Atrioventricular Node Conduction

PURPOSE: The optimal pacing mode with either single chamber atrial pacemaker (AAI or AAIR) or dual chamber pacemaker (DDD or DDDR) is still not clear in sinus-node dysfunction (SND) and intact atrioventricular (AV) conduction. MATERIALS AND METHODS: Patients who were implanted with permanent pacemaker using AAI(R) (n = 73) or DDD(R) (n = 113) were compared. RESULTS: The baseline characteristics were comparable between the two groups, with a mean follow-up duration of 69 months. The incidence of death did not show statistical difference. However, the incidence of hospitalization for congestive heart failure (CHF) was significantly lower in the AAI(R) group (0%) than the DDD(R) group (8.8%, p = 0.03). Also, atrial fibrillation (AF) was found in 2.8% in the AAI(R) group, which was statistically different from 15.2% of patients in the DDD(R) group (p = 0.01). Four patients (5.5%) with AAI(R) developed AV block, and subsequently switched to DDD(R) pacing. The risk of AF was lower in the patients implanted with AAI(R) than those with DDD(R) [hazard ratio (HR), 0.84; 95% confidence interval, 0.72 to 0.97, p = 0.02]. CONCLUSION: In patients with SND and intact AV conduction, AAI(R) pacing can achieve a better clinical outcome in terms of occurrence of CHF and AF than DDD(R) pacing. These findings support AAI(R) pacing as the preferred pacing mode in patients with SND and intact AV conduction.

A case of sinus node dysfunction and atrial tachycardia after the excision of a left atrial myxoma / 대한내과학회지

Atrial myxoma is the most common primary cardiac tumor, and surgical removal is the treatment of choice. Atrial flutter-fibrillation is common after the surgical excision of such tumors, whereas sinus node dysfunction is a rare complication. We detected postoperative sinus node dysfunction and atrial tachycardia after the excision of a left atrial myxoma in a 63-year-old woman. The patient underwent the implantation of a permanent pacemaker two weeks after the operation. The patient underwent successful catheter ablation of macroreentrant right atrial tachycardia 16 months after the operation with no recurrence of atrial tachycardia over the next four months.

Pacientes chagásicos crônicos portadores de disfunção do nódulo sinusal: a presença de anticorpos IgG com ação agonista muscarínica independe da disfunção ventricular esquerda? / Chronic Chagas disease patients with sinus node dysfunction: is the presence of IgG antibodies with muscarinic agonist action independent of left ventricular dysfunction?

Estudos mostram que anticorpos IgG agonistas muscarínicos, de pacientes chagásicos, alteram a atividade elétrica de células cardíacas in vitro. Outros consideram sua presença, e a da síndrome do nódulo sinusal, conseqüências da lesão cardíaca progressiva. Objetivou-se avaliar a relação entre os anticorpos e as disfunções nodal e ventricular esquerda, em 65 pacientes chagásicos crônicos divididos em grupo I, composto de 31 pacientes portadores da síndrome do nódulo sinusal, e grupo II, de não portadores. A análise dos dados, pelo modelo log linear, mostrou uma interdependência entre a disfunção do nódulo sinusal e os anticorpos (p=0,0021) e entre a disfunção nodal e a ventricular (p=0,0005), mas não houve relação entre esta última e os anticorpos. Idade e sexo não tiveram influência sobre as outras variáveis. Chagásicos crônicos com a síndrome do nódulo sinusal têm maior prevalência de anticorpos agonistas muscarínicos, independentemente da presença de disfunção miocárdica.

Studies have shown that muscarinic agonist IgG antibodies from Chagas disease patients alter the electrical activity of cardiac cells in vitro. Others have considered their presence, along with sinus node dysfunction, to be consequences of progressive cardiac lesions. The aim of this study was to evaluate the relationship between these antibodies and sinus node and left ventricular dysfunction in 65 chronic Chagas disease patients. These patients were divided into group I, composed of 31 patients with sinus node dysfunction, and group II, composed of the patients without this syndrome. Data analysis using the log linear model showed interdependence between sinus node dysfunction and the antibodies (p = 0.0021) and between nodal and ventricular dysfunction (p = 0.0005). However, no relationship was found between the antibodies and ventricular function. Age and sex did not influence any other variables. The chronic Chagas disease patients with sinus node dysfunction had higher prevalence of muscarinic agonist antibodies, independent of the presence of myocardial dysfunction.

Successful Treatment of Ischemic Dysfunction of the Sinus Node with Thrombolytic Therapy: A Case Report

We report on a case of ischemic dysfunction of the sinus node as a complication after percutaneous transluminal coronary angioplasty of the distal left circumflex artery. After local thrombolytic therapy in the sinus node artery, sinus node arterial flow was re-established and sinus node function normalized over the period of a week. Our experience suggests that immediate reperfusion of a totally occluded nodal artery can be re-established. Ischemic dysfunction of the sinus node, as a complication of angioplasty, is generally transient and requires a prolonged period for recovery. Therefore the decision to implant a permanent pacemaker should be delayed for at least one week after the ischemic insult.

A Case of Absent Right Superior Vena Cava

Absent right superior vena cava in visceroatrial situs solitus is rare. It has been known the absent right superior vena cava is usually accompanied with persistent left superior vena cava. And this anomaly could be combined witk additional congenital heart disease and rhythm disturbances. We experienced one case of absent right superior vena cava accompanied by persistent left superior vena cava, secundum type atrial septal defect, and transient post-operative sinus node dysfunction.

Electrophysiologic Properties of the AV Conduction System in Patients with Sinus Node Dysfunction / 대한내과학회지

BACKGROUND: It is very important to evalute the function of the atrioventricular conduction system in selecting appropriate pacemaker, pacing and sensing mode in sick sinus syndrome. It has been reported that atrioventricular conduction abnormalities were commonly accompanied with sinus node dysfunction (SND). However, there were several long term follow-up studies indicating that incidence of AV conduction abnormalities was as low as below 1% a year in patients with SND implanted pacemaker. This study was performed to evaluate the properties of the AV conduction system in patients with SND. SUBJECT AND METHODS: Patients subjected to this study were fifty-eight who underwent electrophysiologic study on suspicion of SND. Sinus node recovery time (SNRT) was defined as the longest time among the times that sinus rhythm reappeared after rapid atrial pacing for 45 seconds with several cycle lengths, and corrected SNRT (cSNRT) was worked out by subtracting sinus cycle length (SCL) from SNRT. Criteria for sinus node dysfunction were 1550 msec or more on SNRT, 550 msec or more on cSNRT and group A (23 cases, 58+/-13 yrs) was defined as SND not retrieved to normal after intravenous administration of atropine 1-2 mg, group B (21 cases, 52+/-14 yrs) was retrieved to normal and group C (14 cases, 54+/-13 yrs) was normal control group. Abnormalities of the AV conduction system were defined as 150 msec or more on AH interval, 500 msec or more on AVblock cycle length (AV-BCL), 450 msec or more on AV nodeeffective refractory period (AVN-ERP). RESULTS: SCL in group A, B, C was 1197+/-340 msec, 1215+/-273 msec, and 898+/-129 msec, respectively at baseline and 886+/-218 msec, 798+/-106 msec, and 722+/-110 msec respectively after atropine administration, showing a significant prolongation of SCL in group A and B at baseline (p<0.001) and group A after atropine administration (p<0.05). SNRT in group A, B, C was 3520+/-1817 msec, 3180+/-2390 msec, and 1282+/-116, respectively at baseline and 4155+/-4281 msec, 1237+/-210 msec, 1020+/-245 msec, respectively after atropine administration, showing a significant prolongation of SNRT in group A and B at baseline (p<0.001) and group A after atropine administration (p<0.05). AH intervals at baseline and after atropine administration were 107+/-27 msec and 100+/-20 msec in group A, 101+/-21 and 91+/-14 in group B, and 118+/-32 and 83+/-23 in group C, showing no significant difference between 3 groups. AV-BCLs at baseline and after atropine administration were 428+/-151 msec and 453+/-301 msec in group A, 525+/-140 and 370+/-53 in group B, and 461+/-120 361+/-94 in group C, showing no significant difference between 3 groups. AVN-ERP was 315+/-57 msec in group A, 343+/-132 msec in group B, 347+/-132 in group C, showing no significant difference between 3 groups. There was no significant difference in the incidences of cases with abnormal AH interval, AV-BCL, AVN-ERP, HV interval between 3 groups. AV block greater than second degree was observed in one patient of group A but none of group B and C. CONCLUSIONS: Atrioventricular conduction abnormalities in patients with sinus node dysfunction were not more common than control subjects. Therefore, atrial pacing rather than ventricular or dual chamber pacing may be safely selected as a permanent pacing mode for sick sinus syndrome with no combined significant AV block.