RESUMEN
UNLABELLED: The value of nonfunctional infrahisal second-degree atrioventricular (AV) block induced by incremental atrial pacing was prospectively examined in 192 patients with chronic bundle branch block (BBB) and syncope. We compared 174 (91%) patients with normal response to atrial pacing (Group I) to 18 (9%) patients with atrial pacing induced nonfunctional infrashisal second-degree AV block (Group II). Patients in group I had higher incidence of organic heart disease, ventricular tachycardia induction, and retrograde ventriculoatrial conduction (P < 0.001, P < 0.05, P < 0.01, respectively), while patients in group II had higher incidence of primary conduction disease and prolonged H-V intervals (P < 0.001, P < 0.01, and P < 0.001). During mean follow-up period of 65 +/- 34 months for group I, and 68 +/- 35 months for group II, a development of spontaneous second- or third-degree AV block was higher in group II (14/18 [78%]), than in group I (15/174 [9%]) (P < 0.001). The site of AV block was infrahisal in all patients in group II, and in 10 of 15 patients in group I. Because of the prophylactic pacing in all patients in group II, the incidence of sudden death was similar among the two groups, but patients in group I had higher incidence of cardiac death (P < 0.05). CONCLUSION: In patients with chronic BBB and syncope, a nonfunctional infrashisal AV block induced by incremental atrial pacing identified patients with particularly high risk of development of spontaneous infrahisal AV block. Therefore, permanent cardiac pacing is absolutely indicated in these patients.
Asunto(s)
Fascículo Atrioventricular/fisiopatología , Bloqueo de Rama/terapia , Estimulación Cardíaca Artificial/efectos adversos , Bloqueo Cardíaco/etiología , Síncope/terapia , Adulto , Anciano , Anciano de 80 o más Años , Arritmias Cardíacas/complicaciones , Bloqueo de Rama/complicaciones , Estimulación Cardíaca Artificial/métodos , Muerte Súbita Cardíaca/etiología , Estudios de Evaluación como Asunto , Femenino , Estudios de Seguimiento , Atrios Cardíacos , Bloqueo Cardíaco/clasificación , Cardiopatías/complicaciones , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores de Riesgo , Síncope/complicaciones , Taquicardia Ventricular/complicacionesRESUMEN
In 71 patients with a myocardial infarction (MI) (anterior in 27, inferior in 44 patients) global (GEF) and regional (REF) left ventricular ejection fractions were determined by radionuclide ventriculography and estimated from a 12 lead electrocardiogram (ECG), using Selvester's QRS score, during the early phase of a MI (15 to 21 days following MI). Global ejection fractions determined by radionuclide ventriculography and from ECG using Palmeri's method were: for all MI 40.8 +/- 12.6% vs 39.6 +/- 11.4%; in the group of anterior MI 32.0 +/- 10.0% vs 30.0 +/- 9.7% and in the group of inferior MI 48.9 +/- 12.0% vs 45.1 +/- 8.2%. A good correlation was found between global ejection fractions determined by radionuclide ventriculography and ECG, as well as between radionuclide GEF and ECG score. A weaker correlation was found between radionuclide GEF and enzymes among all MIs and in the group of anterior MI, while in the group of inferior MI this correlation was insignificant. The analysis of REF determined by radionuclide ventriculography and ECG showed the greatest abnormalities in the infarct region, but in the group of anterior MI, dysfunction was present in the whole left ventricle. The comparison of infarct-related REF derived from radionuclide ventriculography, with the QRS score showed a significantly higher correlation than the comparison with enzymes. ECG estimation of REF from a modified Palmeri's equation showed a better correlation with radionuclide REF than did GEF derived from the standard Palmeri's equation: anterior MI; r = 0.90 vs r = 0.82, inferior MI; r = 0.84 vs r = 0.69, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Electrocardiografía/instrumentación , Infarto del Miocardio/fisiopatología , Procesamiento de Señales Asistido por Computador/instrumentación , Volumen Sistólico/fisiología , Función Ventricular Izquierda/fisiología , Adulto , Anciano , Electrocardiografía/estadística & datos numéricos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/mortalidad , Valores de Referencia , Tasa de SupervivenciaRESUMEN
Quantitative and qualitative analyses of Q waves and QRS scores were performed on 69 patients during the early phase of first myocardial infarction (MI) and 6 months subsequently. The regression of ECG signs of MI were compared with the enzymatically estimated size of MI, the location of MI, and with the changes of global ejection fraction (GEF) assessed by radionuclide ventriculography. Among 57 patients with Q wave MI a complete disappearance of ECG signs of MI was found in 9 (15.7%). Patients with MI of inferior location showed a significantly higher reduction of Q waves (p < 0.001) and QRS scores (p < 0.001) than the anterior MI group. In the group of 12 patients with non Q wave MI, 11 demonstrated complete regression of MI signs. Among all Q wave and non Q wave MIs, the authors found no significant difference in the size of MI between patients with and without complete regression of ECG signs of MI. The median of the percent of change of the QRS score was significantly higher (p = 0.04) in the group of patients with improved GEFs than in the group of patients with decreased or unchanged GEFs 6 months following acute MI. The sensitivity, specificity, and predictive values for improved left ventricular function according to the change of Q waves and ECG scores were 91%, 32%, and 62%; for changes of Q waves, 81%, 40%, and 63%; and for changes of ECG scores, 91%, 36%, and 64%, respectively. In the group of patients with non Q wave MI these values were 100%, 50%, and 91% as a result of ST-T disappearance.
Asunto(s)
Electrocardiografía , Infarto del Miocardio/fisiopatología , Miocardio/patología , Función Ventricular Izquierda , Pruebas Enzimáticas Clínicas , Creatina Quinasa/sangre , Estudios de Seguimiento , Humanos , Isoenzimas , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/patología , Valor Predictivo de las Pruebas , Estudios Prospectivos , Sensibilidad y Especificidad , Volumen SistólicoRESUMEN
In 60 patients myocardial infarction size was determined by electrocardiogram (ECG) using Selvester's QRS scoring system. These values were compared with the size of infarction as determined enzymatically using gram equivalent isoenzyme MB creatine kinase (gEq) and using maximum values of isoenzyme MB-CK. The results showed no statistically significant difference between the size of anterior and inferior infarction determined by gEq (25.19 +/- 13.59 vrs 22.48 +/- 14.04; p = 0.12 NS) and by maximum MB-CK (125.5 +/- 76.0 vrs 98.4 +/- 60.7; p = 0.12 NS). The size of myocardial infarctions determined by ECG was significantly larger anteriorly compared with the inferior infarcts (9.6 +/- 2.9 vrs 4.5 +/- 2.6; p = 0.001). In patients with anterior infarcts good correlations between the size of infarction determined by QRS scoring system and by gEq or maximum MB-CK were found (r = 0.69; p = 0.004 and r = 0.72; p = 0.001). In patients with inferior infarcts the correlations between QRS score and gEq or maximum MB-CK were poor (r = 0.37; p = 0.02 and r = 0.45; p = 0.15). The causes of weak correlations in the results of described methods in inferior infarcts are discussed. Thus QRS scoring system provides new noninvasive and simple possibilities in determining the size of anterior and in inferior infarctions of the left ventricle.