Sinus node dysfunction during transcatheter assessment and stent correction of sinus venosus atrial septal defects.

Covered stent correction of a superior sinus venosus atrial septal defect is increasingly performed as an alternative to surgical repair. While sinus node dysfunction requiring pacemaker implantation may be required after surgical repair, this has not been previously reported after covered stent implantation. We reviewed the experience in two interventional centers. Balloon inflation in the superior vena cava was used to confirm the anomalous pulmonary vein drainage would be unobstructed after stent implantation. During balloon testing in 62 consecutive patients, we assessed gradients across the pulmonary vein to left atrium while monitoring the rhythm. We observed the outcomes after covered stent correction in 51 patients. In a single patient, significant bradycardia and pauses developed on repeat balloon testing and the procedure was abandoned without stent implantation. In another patient, there was no sign of sinus node dysfunction during balloon testing but several hours after stent implantation, the patient became symptomatic from sinus bradycardia and pauses and had a pacemaker implanted 3 days later. Over a year later there are some signs of improvement in sinus node function. While sinus node dysfunction has not been described previously during balloon testing or after stent implantation, this report demonstrates for the first time that it may occur. Larger registries are therefore required to monitor for this uncommon complication.

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.

[Left bundle branch stimulation in diffuse electrical heart disease in a pediatric patient]. / Estimulación de rama izquierda en enfermedad eléctrica difusa cardiaca en una paciente pediátrica.

Left bundle branch stimulation is a second-line strategy in patients where His bundle stimulation is not optimal. Currently, no cases of left bundle branch stimulation have been reported in patients with diffuse electrical cardiac disease or in the pediatric population.

Conduction Disorders: The Value of Surface ECG.

PURPOSE OF REVIEW: The purpose of the current mini-review is to describe the importance of surface ECG for the diagnosis of conduction disorder. METHODS: The MEDLINE/PubMed database was used, with the keywords "ECG" and "conduction disorders"; over the past 10 years. Other documents were included because of their relevance. MAIN FINDINGS: Data on the anatomy and function of the cardiac electrical system have been described. Conduction disorders including sinus node dysfunction, atrioventricular blocks, intraventricular conduction disorders are exposed as to their epidemiology, etiology, presentation, anatomical site of impaired conduction of the electrical stimulus. The importance of ECG in patients with a cardiac implantable electronic device was also discussed, in addition to future perspectives. CONCLUSION: Surface ECG allows the diagnosis of atrioventricular and intraventricular conduction disorder and its anatomical block site most of the time, without the need for invasive tests such as electrophysiological study. Dysfunctions of cardiac implantable electronic devices can be diagnosed by ECG, as well as the prediction of response to cardiac resynchronization therapy.

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.