ABSTRACT
Objective To observe the parameters and effect of endocardial pacing by steel wire electrode cardiac puncture on heart with normal beat in living animal, and evaluate its safety.Methods After anaesthesia and thoracotomy in 6 living dogs with normal heart beat, the pericardia were excised. Steel wire electrodes with annular or hook tips were used respectively at right ventricular 4 corresponding spots to perform cardiac puncture endocardiac pacing (each dog experienced 8 times of puncture); the time from puncture to effective pacing, pacing parameter and puncture complication (time and quantity of bleeding) of each electrode at each spot were recorded. Finally, the two types of electrode completed 24 times of manipulation respectively; the data collected of the two types were compared. Results The cardiac pacing successful rates in the two groups were 100%; the time taken from the beginning of heart puncture to effective pacing in annular tip group was less than that in hook tip group, but the time difference between the two groups showed no statistical significance (s: 18.4±2.3 vs. 19.6±4.1,P > 0.05). The parameters of pacing in the annular tip group, such as operation time (s: 18.4±2.3 vs. 19.6±4.1), the threshold value of pacing (V: 2.1±0.2 vs. 2.2±0.8), the amplitude of R wave sensed (mV: 11.3±3.2 vs. 12.6±4.1) and the impedance of electrode (Ω: 674.2±89.7 vs. 668.5±101.3) were not significantly different compared with those in the hook tip group (allP > 0.05). Either after puncture or after the electrodes were taken out, the time of bleeding [after puncture (minutes): 4.4±2.3 vs. 4.5±3.1, after the electrodes taken out (minutes): 4.1±2.2 vs. 4.8±2.5] and the volume of bleeding [after puncture (mL): 2.8±2.4 vs. 3.2±3.5, after the electrodes taken out (mL): 3.3±1.7 vs. 3.5±2.6] were not significantly different between the two groups (allP > 0.05).Conclusions In living dogs with normal heart beat, the manipulation and function of endocardiac pacing by cardiac puncture with either steel wire annular or hook tip electrode are well and effective, and the performance is simple and safe without any serious myocardial injury and complication. Thus, it is helpful to quickly establish efficient endocardiac pacing in emergency cases.
ABSTRACT
La muerte súbita cardíaca de causa eléctrica en sujetos con corazón "sano", constituye un problema clínico y de salud pública, aún no resuelto. Los objetivos del trabajo fueron: caracterizar pacientes reanimados de un evento de muerte súbita de causa eléctrica y conocer su evolución intervenida en tres años; y estudiar los signos eléctricos premonitorios de muerte súbita. Se estudiaron 42 sujetos, 30 hombres y 12 mujeres, edad promedio 37.7 años, con corazón "sano", por métodos clínicos y paraclínicos. Se consideraron 9 subpoblaciones, en mayor número los síndromes de Brugada y de QT largo y la fibrilación ventricular idiopática. Las arritmias responsables del evento fueron, en primer lugar, la fibrilación ventricular y la torsión de puntas. Existieron signos premonitorios en el 92.8% de los pacientes. Fueron frecuentes las recidivas de las arritmias malignas (71.4%) aunque en la estimulación eléctrica programada, sólo se logró reproducirlas en 4 de 18 pacientes. La fibrilación auricular predominó como arritmia coexistente (19%). En resumen, son frecuentes los signos premonitorios (en especial la fibrilación auricular) y las recidivas de las arritmias malignas aunque su inducibilidad en el laboratorio es pobre. La estratificación de riesgo es muy difícil, por el bajo valor predictivo de los métodos diagnósticos.
Sudden cardiac death due to electrical causes in individuals with no evidence of structural heart disease is an important clinical and public health problem, and it is not yet solved. The objectives of this study were: to characterize patients reanimated from a sudden death event of electrical cause; to know the mediated evolution during a period of three years and to study premonitory electrical signs. 42 individuals were studied, 30 were male and 12 female, mean age 37.7 years, healthy heart, by clinic and paraclinic methods. Nine subpopulations were studied, being Brugada syndrome, long QT syndrome and idiopathic ventricular fibrillation the most frequent. Ventricular fibrillation and twisting of the points were the arrhythmias responsible for most death events. There were premonitory signs in 92.8% and clinical recurrences of life-threatening events in 71.4% but they were induced during programmed electrical stimulation only in 4 of 18 patients. Atrial fibrillation was the most frequent coexistent arrhythmia (19%). In summary, there are frequent premonitory signs (particularly atrial fibrillation), and also malignant arrhythmic recurrences but a poor inducibility at the electrophysiology laboratory. It is very difficult to stratify the risk because of the low predictive value of diagnostic methods.
Subject(s)
Adolescent , Adult , Child , Child, Preschool , Female , Humans , Male , Arrhythmias, Cardiac/complications , Death, Sudden, Cardiac/etiology , Heart Arrest/etiology , Anti-Arrhythmia Agents/therapeutic use , Arrhythmias, Cardiac/diagnosis , Arrhythmias, Cardiac/drug therapy , Cuba/epidemiology , Death, Sudden, Cardiac/epidemiology , Death, Sudden, Cardiac/prevention & control , Defibrillators, Implantable , Electrocardiography , Electrophysiologic Techniques, Cardiac , Heart Arrest/epidemiology , Heart Arrest/therapy , Risk FactorsABSTRACT
Cardiovascular diseases have been the most serious threat to life and health. The socioeconomic ramifications of heart disease have long been a source of vexing legal as well as medical problems with no easy resolution as yet in hand. Heart weight, one of the important factors for the diagnosis of cardiomegaly and various heart diseases, shows extreme variability according to the height, weight, age, sex, nutritional status of individuals as well as other various factors. The purpose of this investigation was to find a practical method for calculating expected normal range of heart weight in a given individual. The study was performed on 259 autopsy cases of normal Korean men and women, consisting of 123 men and 136 women in age from newborn to 77 years old. Height, body weight, and heart weight were measured and the body surface area was calculated by height (cm)0.725 x weight (kg)0.425 x 71.84 and height (cm)0.7763 x weight (kg)0.4081 x 71.84 in men and women, respectively. The results showed that the mean heart weight of men and women older than 20 years old were 316.20 +/- 51.15 g (n=96) and 275.87 +/- 44.69 g (n=108), respectively. Heart weight was gradually increased according to the age. The body weight (men: r=0.81, women: r=0.84) and body surface area (men: r=0.83, women: r=0.83) were better univariate predictors of normal heart weight than body height (men: r=0.78, women: r=0.75) and age (men: r=0.42, women: r=0.57). No significant difference was found in predictive precision between body weight and body surface area. Since the body surface area was calculated from body weight and height, measuring the body weight was essential for calculating expected normal range of heart weight in a given individual, and calculation of expected normal range of heart weight using body weight was simpler method than using body surface area.