QT interval greater than 460 ms in multiple electrocardiograms during follow-up in patients with Brugada syndrome: What does it contribute?

INTRODUCTION: Corrected QT interval (QTc) >460 ms in the right precordial leads has been described as a predictor of malignant ventricular arrhythmias (MVA) in patients with Brugada syndrome (BrS). OBJECTIVE: To assess the presence of QTc>460 ms in multiple electrocardiograms (ECGs) during follow-up as a predictor of recurrence of MVA in patients with BrS. METHODS: The study group included 43 patients with BrS and an implantable cardioverter-defibrillator. ECGs were performed serially between June 2000 and January 2017. QT interval was measured and QTc was obtained by Bazett's formula. The sample was divided into three groups: Group 1 (patients with no ECGs with QTc>460 ms); Group 2 (patients with only one ECG with QTc>460 ms); and Group 3 (patients with two or more ECGs with QTc>460 ms). RESULTS: The following variables were more frequently observed in Group 3: family history of sudden death (p=0.023), previous history of cardiorespiratory arrest (p=0.032), syncope (p=0.039), documented MVA (p=0.002), and proportion of ECGs with coved-type ST interval during follow-up (p=0.002). In Group 3, 67% of BrS patients had events during follow-up, as opposed to only 22% of Group 1 and 14% of Group 2 (Group 1 vs. Group 2, p=0.33015; Group 1 vs. Group 3, p=0.04295; and Group 2 vs. Group 3, p=0.04155). CONCLUSIONS: QTc>460 ms in more than one ECG during follow-up increases the risk of MVA events in patients with BrS.

Hematoma renal subcapsular secundario a angiografía coronaria / Subcapsular renal hematoma secondary to coronary angiography

RESUMEN Mujer de 72 años de edad, con antecedentes de angina de esfuerzo estable, a quien tras presentar un síndrome coronario agudo sin elevación del segmento ST, se le realizó angiografía coronaria convencional (invasiva), donde se evidenció enfermedad arterial coronaria multivaso con estenosis significativa del tronco coronario izquierdo y se decidió tratamiento quirúrgico. A los 70 minutos presentó dolor en el flanco izquierdo y región lumbar ipsilateral, náuseas y vómitos. Al examen físico inicial se evidenció masa palpable, dolorosa, en flanco izquierdo. La tomografía demostró la presencia de un hematoma renal subcapsular izquierdo. Al cuadro de abdomen agudo se sumó choque hipovolémico, por lo que la paciente fue intervenida quirúrgicamente, donde se comprobó el diagnóstico tomográfico y se realizó nefrectomía. Este caso tiene la curiosidad de presentar factores predisponentes para causa espontánea y traumática; sin embargo, en base a los hallazgos en el estudio anatomopatológico se concluyó como hematoma renal subcapsular de origen traumático.

ABSTRACT A 72-year-old woman, with a history of stable effort angina, who was performed, after presenting a non-ST segment elevation acute coronary syndrome, a conventional coronary angiography (invasive) that evidenced the multivessel coronary artery disease with significant stenosis of the left main coronary artery, therefore, a surgical treatment was decided. At 70 minutes she presented pain in the left side and ipsilateral lumbar region, nausea and vomiting. The initial physical examination evidenced a palpable, painful mass in the left side. The tomography showed the presence of a left subcapsular renal hematoma. To the acute abdomen pattern was added a hypovolemic shock, thus, the patient underwent surgery, confirming the tomographic diagnosis and performing a nephrectomy. This particular case presented predisposing factors for spontaneous and traumatic cause; however, based on the findings in the anatomopathological study, the conclusion was a renal subcapsular hematoma of traumatic origin.

Importancia de la sincronía aurículo-ventricular para el gasto cardíaco en un paciente con insuficiencia cardíaca y fracción de eyección reducida / Importance of atrioventricular synchrony for cardiac output in a patient with heart failure and reduced ejection fraction

RESUMEN Hombre de 80 años de edad, con antecedentes de miocardiopatía dilatada de origen isquémico, con disfunción sisto-diastólica del ventrículo izquierdo, que inicialmente presentó flutter auricular con inestabilidad hemodinámica y se realizó cardioversión eléctrica, luego de la cual se obtuvo un ritmo no precedido de onda P a 40 latidos por minuto, que fue interpretado como fibrilación auricular bloqueada; razón por la que se le colocó un marcapasos externo. Durante su evolución se realizó electrocardiograma de 12 derivaciones, donde se evidenció estimulación ventricular permanente con conducción retrógrada (ventrículo-auricular). Se disminuyó la frecuencia de estimulación para priorizar el ritmo espontáneo del paciente y se obtuvo marcada mejoría de la curva de presión arterial.

ABSTRACT An 80-year-old male patient is presented, with previous dilated cardiomyopathy of ischemic etiology, with systo-diastolic left ventricular dysfunction, who initially presented atrial flutter and hemodynamic instability, thus, an electrical cardioversion was performed. After this procedure, a blocked atrial fibrillation was observed. Thus, an external pacemaker was placed. During the evolution, a 12 lead electrocardiogram was performed, showing permanent ventricular stimulation with retrograde conduction (ventriculo-atrial). The pacing rate was diminished for prioritizing the patient's spontaneous rhythm resulting in an improvement of the blood pressure curve.

Multiple serial ECGs aid with the diagnosis and prognosis of Brugada syndrome.

BACKGROUND: A spontaneous coved-type ST segment elevation in the electrocardiogram (ECG) has long been recognized as a risk stratification tool in patients with Brugada syndrome (BrS). This Type-I ST segment elevation is known to exhibit high dynamicity, fluctuating between coved-type and non-coved ST segment elevation. Our objectives in this study were to: 1) Compare ECG parameters in patients with spontaneous coved-type (Type-I) vs. non-coved-type ST segment ECGs; 2) Determine the variability of these ECG parameters with repeated measurements; and 3) Assess the predictive value of ECG parameters in these two groups during follow-up. METHODS: Forty-two consecutive patients with BrS and implanted ICD were studied between 2000 and 2017. Serial ECGs and clinical characteristics were obtained over a period of 199 months. RESULTS: QT-interval, QTc-interval, QRS duration, Tp-e interval and Tp-e dispersion were all significantly longer in spontaneous Type I vs. non-Type 1 ECGs and all ECG parameters displayed significant variability during serial recording obtained throughout the follow-up period. Patients with a spontaneous Type I ECG during the 114 ±â€¯56 months follow-up period were at a much higher risk for VT/VF than those without a Type I ECG (p = 0.016). Moreover, the risk for development of life-threatening ventricular arrhythmias was directly related to the fraction of ECGs displaying a spontaneous Type I pattern during follow-up. CONCLUSION: Our study illustrates the need for multiple ECGs to aid with both the diagnosis and prognosis of BrS. Serial ECGs can assist with risk stratification based on the fraction of ECGs that display a spontaneous Type-I BrS ECG.

Prolongación de la despolarización y la repolarización ventriculares en pacientes operados de cirugía cardíaca

Introducción: La cirugía cardíaca establece una serie de elementos mecánicos y químicos de agresión al musculo cardíaco, que pudiese verse reflejada en el electrocardiograma. Objetivo: Evaluar si las medidas electrocardiográficas que reflejan la despolarización y la repolarización ventriculares se prolongan posterior a la cirugía cardíaca. Método: Se estudiaron 51 pacientes con cirugía cardíaca, a quienes se les realizó electrocardiograma antes y después del procedimiento. Se comparó, mediante la prueba T, la diferencia de los valores de intervalo QT, QTc, dispersión del QT, intervalo TPICO-TFINAL (TP-F), dispersión del TP-F y duración del QRS, antes y después de la intervención quirúrgica. Resultados: Los valores del QTc, dispersión del QT, TP-F, dispersión del TP-F y duración del QRS fueron significativamente mayores (p<0,006) en el electrocardiograma posterior a la cirugía. El intervalo QT sin corregir fue mayor en el electrocardiograma posquirúrgico, sin diferencia estadísticamente significativa (p=0,49). Conclusiones: La agresión al músculo cardíaco durante la cirugía cardíaca modifica la actividad eléctrica ventricular y se constata en la prolongación significativa de las mediciones que reflejan la despolarización y repolarización ventriculares. Estas variables pudieran utilizarse en futuros estudios como predictores de eventos adversos de este procedimiento.

Introduction: Cardiac surgery involves a series of aggressive mechanical and chemical elements that affect the cardiac muscle; which may be shown by the electrocardiogram. Objective: To evaluate whether electrocardiographic measurements reflecting ventricular depolarization and repolarization are prolonged after cardiac surgery. Method: We studied 51 patients with cardiac surgery who underwent an electrocardiogram before and after surgery. The difference between QT, QTc, QT dispersion, TPEAK-TEND interval (TP-TE), TP-TE dispersion and QRS duration, before and after surgery was compared using the T test. Results: Electrocardiogram after surgery showed significantly higher QTc values, QT dispersion, TP-TE, TP-TE dispersion and QRS duration (p<0.006). The uncorrected QT interval was greater in the postoperative electrocardiogram, without statistically significant difference (p=0.49). Conclusions: Myocardial aggression during cardiac surgery modifies the ventricular electrical activity and is verified by the significantly prolonged depolarization and repolarization measurements. These variables could be used in future studies as predictors of adverse events in this procedure.

Bloqueo aurículoventricular completo aislado: a propósito de un caso / Complete atrioventricular block: a case report

Se trata de paciente masculino de 2 años, asintomático que en control de rutina se evidencia bradicardia (40lpm). Mediante electrocardiograma se realiza el diagnóstico de bloqueo auriculoventricular completo (BAVC). Se realiza ecocardiograma sin alteración funcional ni estructural. Por lo antes mencionado se concluye como un BAVC congénito aislado en un paciente asintomático con una frecuencia ventricular insuficiente por lo que se le implantó un marcapasos permanente (modo VVI) sin complicaciones.

A 2-year-old male patient, asymptomatic with bradycardia (40bpm) in a routine examination. Using electrocardiogram the diagnosis of complete atrioventricular block (CAVB) was made. Echocardiogram was performed and showed no functional or structural disease. We conclude like an asymptomatic congenital isolated CAVB with insufficient ventricular rate, for this reason a permanent pacemaker (VVI mode) was implanted, without complications.