Criação de um sistema de apoio para o suporte avançado de vida

Dissertação de mestrado integrado em Engenharia Biomédica (área de especialização em Eletrónica Médica)

Coronary arterial disease after electroconvulsive therapy: a case report

Objectives Unipolar depression (UPD) is a leading cause of global burden of diseases, particularly among the elderly, whose treatment may be challenging. In such cases, ECT is often recommended due to its safety and efficacy. This report presents a case of a 67-year-old male inpatient that developed a rare cardiac complication during ECT. Methods Clinical case report with patient’s consent and bibliographic review. Results A 67-year-old male inpatient with recurrent severe psychotic depression was hospitalized and ECT was indicated after failure of the pharmacological treatment. A comprehensive clinical pre-evaluation revealed only nonspecific ST-segment changes in electrocardiogram. During the 7th ECT session, it was observed transitory ST-segment depression followed by a discrete increase of plasma troponin I. Severe tri-vessel coronary artery stenosis was found and a percutaneous coronary angioplasty was performed, with satisfactory psychiatric and cardiac outcomes. Conclusions Unipolar depression (UPD) and cardiovascular disease are often coexistent conditions, especially among the elderly. In the current case, myocardial ischemia was detected lately during ECT therapy and its treatment allowed the UPD treatment to be completed adequately.

Evaluation of the heart rate and arrhythmias following the Maze procedure for chronic atrial fibrillation

PURPOSE: To assess the presence and the prevalence of arrhythmias and the variability of the heart rate in the medium-term postoperative period following the maze procedure for chronic atrial fibrillation (AF). METHODS: Seventeen patients with a mean age of 51.7±12.9 years, who previously underwent the maze procedure without cryoablation for chronic atrial fibrillation, were evaluated with the 24 hour electrocardiogram (ECG) - Holter monitoring from the 6th month after the operation. Valvular and coronary procedures were concomitantly performed. RESULTS: The mean heart rate during Holter monitoring was 82±8bpm; the maximal heart rate was 126 ± 23bpm and the minimal heart rate 57±7bpm. Sinus rhythm was found in 10 (59%) patients and atrial rhythm was found in 7 (41%). Supraventricular extrasystoles had a rate of 2.3±5.5% of the total number of heartbeats and occurred in 16 (94%) patients. Six (35%) patients showed nonsustained atrial tachycardia. Ventricular extrasystoles, with a rate of 0.8±0.5% of the total heartbeats, occurred in 14 (82%) patients. The chronotropic competence was normal in 9 (53%) patients and attenuated in 8 (47%). The atrioventricular conduction (AV) was unchanged in 13 (76%) patients and there were 4 (24%) cases of first degree atrioventricular block (AVB). CONCLUSION: After the maze procedure, the values for the mean heart rate, AV conduction and chronotropic competence approach the normal range, although some cases show attenuation of the chronotropic response, first degree AV block or benign arrhythmias.

Difference in the in-hospital mortality of unstable angina pectoris between men and women

PURPOSE: To assess differences in the in-hospital mortality (HM) rate between men and women with unstable angina pectoris (UA) according to age, depression of the ST segment, history of previous acute myocardial infarction (AMI), and risk factors for coronary heart disease. METHODS: From October 96 to March 98, 261 patients with UA were selected. Logistic regression models were developed to adjust the association between sex and HM for possible influence of covariables, such as hypertension, diabetes mellitus, dyslipidemia, sedentary lifestyle, smoking, and familial history of early coronary heart disease. RESULTS: HM due to UA was approximately three times higher in women (9.3%; 12/129) than in men (3.0%; 4/132) accounting for a relative risk of 3.07; 95% confidence interval (CI) =1.02-9.27. In logistic regression models, the association between sex and death was not significantly altered when the following parameters were considered: age, depression of the ST segment, history of previous AMI and risk factors for coronary heart disease. The nonadjusted and adjusted odds ratio (OR) for the distinct covariables were 3.28 (CI 95%=1.03-10.45) and 3.14 (CI = 95% = 0.88-11.20), respectively. CONCLUSION: Similarly to AMI, HM in UA is higher in women than in men. Age, risk factors for coronary heart disease, and depression of the ST segment in the electrocardiogram on patients' admission to the hospital did not significantly influence the association between sex and death.

Influence of the elevation of the left ventricular diastolic pressure on the values of the first temporal derivative of the ventricular pressure (dP/dt)

PURPOSE: To assess the effects of the elevation of the left ventricular end-diastolic pressure (LVEDP) on the value of the 1st temporal derivative of the ventricular pressure (dP/dt). METHODS: Nineteen anesthetized dogs were studied. The dogs were mechanically ventilated and underwent thoracotomy with parasympathetic nervous system block. The LVEDP was controlled with the use of a perfusion circuit connected to the left atrium and adjusted to the height of a reservoir. The elevation of the LVEDP was achieved by a sudden increase in the height of a reservoir filled with blood. Continuous recordings of the electrocardiogram, the aortic and ventricular pressures and the dP/dt were performed. RESULTS: Elevation of the LVEDP did not result in any variation of the heart rate (167±16.0bpm, before the procedure; 167±15.5bpm, after the procedure). All the other variables assessed, including systolic blood pressure (128±18.3mmHg and 150±21.5mmHg), diastolic blood pressure (98±16.9mmHg and 115±19.8mmHg), LVEDP (5.5±2.49 and 9.3±3.60mmHg), and dP/dt (4,855 ± 1,082 mmHg/s and 5,149±1,242mmHg/s) showed significant increases following the expansion of the ventricular cavity. Although the elevation of the dP/dt was statistically significant, 6 dogs curiously showed a decrease in the values of dP/dt. CONCLUSION: Sudden elevation of the LVEDP resulted in increased values of dP/dt; however, in some dogs, this response was not uniform.

Effects of carvedilol in heart failure due to dilated cardiomyopathy. Results of a double-blind randomized placebo-controlled study (CARIBE study)

OBJECTIVE: To assess the effects of carvedilol in patients with idiopathic dilated cardiomyopathy. METHODS: In a double-blind randomized placebo-controlled study, 30 patients (7 women) with functional class II and III heart failure were assessed. Their ages ranged from 28 to 66 years (mean of 43±9 years), and their left ventricular ejection fraction varied from 8% to 35%. Carvedilol was added to the usual therapy of 20 patients; placebo was added to the usual therapy of 10 patients. The initial dose of carvedilol was 12.5 mg, which was increased weekly until it reached 75 mg/day, according to the patient's tolerance. Clinical assessment, electrocardiogram, echocardiogram, and radionuclide ventriculography were performed in the pretreatment phase, being repeated after 2 and 6 months of medication use. RESULTS: A reduction in heart rate (p=0.016) as well as an increase in left ventricular shortening fraction (p=0.02) and in left ventricular ejection fraction (p=0.017) occurred in the group using carvedilol as compared with that using placebo. CONCLUSION: Carvedilol added to the usual therapy for heart failure resulted in better heart function.

Right coronary artery fistula with congestive heart failure in the neonate. Doppler echocardiographic diagnosis and closure with detachable balloon

We report here a case of coronary artery fistula in a neonate with clinical signs of heart failure. The electrocardiogram showed signs of left ventricular hypertrophy and diffuse alterations in ventricular repolarization. Chest X-ray showed an enlargement of the cardiac silhouette with an increase in pulmonary flow. After echocardiographic diagnosis and angiographic confirmation, closure of the fistulous trajectory was performed with a detachable balloon with an early and late successful outcome.

Arrhythmogenic cardiomyopathy of the right ventricle. Predictive value of QT interval dispersion to assess arrhythmogenic risk and sudden death

OBJECTIVE: To determine in arrhythmogenic right ventricular cardiomyopathy the value of QT interval dispersion for identifying the induction of sustained ventricular tachycardia in the electrophysiological study or the risk of sudden cardiac death. METHODS: We assessed QT interval dispersion in the 12-lead electrocardiogram of 26 patients with arrhythmogenic right ventricular cardiomyopathy. We analyzed its association with sustained ventricular tachycardia and sudden cardiac death, and in 16 controls similar in age and sex. RESULTS: (mean ± SD). QT interval dispersion: patients = 53.8±14.1ms; control group = 35.0±10.6ms, p=0.001. Patients with induction of ventricular tachycardia: 52.5±13.8ms; without induction of ventricular tachycardia: 57.5±12.8ms, p=0.420. In a mean follow-up period of 41±11 months, five sudden cardiac deaths occurred. QT interval dispersion in this group was 62.0±17.8, and in the others it was 51.9±12.8ms, p=0.852. Using a cutoff > or = 60ms to define an increase in the degree of the QT interval dispersion, we were able to identify patients at risk of sudden cardiac death with a sensitivity of 60%, a specificity of 57%, and positive and negative predictive values of 25% and 85%, respectively. CONCLUSION: Patients with arrhythmogenic right ventricular cardiomyopathy have a significant increase in the degree of QT interval dispersion when compared with the healthy population. However it, did not identify patients with induction of ventricular tachycardia in the electrophysiological study, showing a very low predictive value for defining the risk of sudden cardiac death in the population studied.

Multiple arterial anomalies in the newborn infant. Echocardiographic and angiographic diagnosis

Multiple arterial anomalies characterized by tortuosity and rolling of the pulmonary arteries and aorta were diagnosed on echocardiography in an asymptomatic newborn infant with a phenotype suggesting Ehlers-Danlos syndrome. These changes were later confirmed on angiography, which also showed peripheral vascular abnormalities. The electrocardiogram showed a probable hemiblock of the left anterosuperior branch, and the chest x-ray showed an excavated pulmonary trunk with normal pulmonary flow.

Gas exchange during exercise in different evolutional stages of chronic Chagas' heart disease

OBJECTIVE: To compare gas exchange at rest and during exercise in patients with chronic Chagas' heart disease grouped according to the Los Andes clinical/hemodynamic classification. METHODS: We studied 15 healthy volunteers and 52 patients grouped according to the Los Andes clinical/hemodynamic classification as follows: 17 patients in group IA (normal electrocardiogram/echocardiogram), 9 patients in group IB (normal electrocardiogram and abnormal echocardiogram), 14 patients in group II (abnormal electrocardiogram/echocardiogram, without congestive heart failure), and 12 patients in group III (abnormal electrocardiogram/echocardiogram with congestive heart failure). The following variables were analyzed: oxygen consumption (V O2), carbon dioxide production (V CO2), gas exchange rate (R), inspiratory current volume (V IC), expiratory current volume (V EC), respiratory frequency, minute volume (V E), heart rate (HR), maximum load, O2 pulse, and ventilatory anaerobic threshold (AT). RESULTS: When compared with the healthy group, patients in groups II and III showed significant changes in the following variables: V O2peak, V CO2peak, V ICpeak, V ECpeak, E, HR, and maximum load. Group IA showed significantly better results for these same variables as compared with group III. CONCLUSION: The functional capacity of patients in the initial phase of chronic Chagas' heart disease is higher than that of patients in an advanced phase and shows a decrease that follows the loss in cardiac-hemodynamic performance.

Pseudo-myocardial infarction during an episode of herpes zoster

The patient arrived at the emergency unit with a history of acute myocardial infarction, for which she was treated. Without improvement in the pain, the patient developed heart failure and underwent a hemodynamic study, which showed normal coronary arteries and extensive ventricular impairment. During evolution, the clinical findings improved and herpes zoster appeared on the right shoulder. In a few months the clinical findings subsided, and the findings of the electrocardiogram, chest X-ray, and ventricular function were normal. The patient is currently asymptomatic.

Effects of chlorthalidone and diltiazem on myocardial ischemia in elderly patients with hypertension and coronary artery disease

OBJETIVE: Antihypertensive therapy with thiazides decreases coronary events in elderly patients. However, the influence of diuretics on myocardial ischemia has not been fully investigated. The aim of this study was to compare the effect of chlorthalidone and diltiazem on myocardial ischemia. METHODS: Following a randomized, double-blind, crossover protocol, we studied 15 elderly hypertensive patients aged 73.6±4.6 years with myocardial ischemia. All patients had angiographically documented coronary artery disease. We measured patients using 48- hour ambulatory electrocardiogram monitoring and exercise testing. After a 2-week period using placebo, patients received chlorthalidone or diltiazem for 4 weeks. RESULTS: Both treatments lowered systolic and diastolic blood pressures. The number of ischemic episodes on ambulatory electrocardiogram recordings was reduced with the use of chlorthalidone (2.5±3.8) and diltiazem (3.2±4.2) when compared with placebo (7.9±8.8; p<0.05). The total duration of ischemic episodes was reduced in both treatments when compared with placebo (chlorthalidone: 19.2±31.9min; diltiazem: 19.3±29.6min; placebo: 46.1±55.3min; p<0.05). CONCLUSION: In elderly hypertensive patients with coronary artery disease, chlorthalidone reduced myocardial ischemia similarly to diltiazem. This result is consistent with epidemiological studies and suggests that reduction of arterial blood pressure with thiazide therapy plays an important role in decreasing myocardial ischemia.

Chagas' heart disease: evolutive evaluation of electrocardiographic and echocardiographic parameters in patients with the indeterminate form

OBJECTIVE: To identify and associate potential electrocardiographic and echocardiographic changes in patients with the indeterminate form of Chagas' disease during long-term follow-up. METHODS: One hundred sixty patients underwent standard electrocardiography and two-dimensional guided M-mode echocardiography for left ventricular ejection fraction determination. Patients were followed up for 98.6±30.4 months, undergoing repeat electrocardiographic studies at 6-month intervals and echocardiographic studies at 12-month intervals. RESULTS: Based on the electrocardiographic findings, the patients were divided into group I, 125 patients (78.6%) with normal electrocardiograms throughout follow-up, and group II, 34 patients (21.3%) who developed electrocardiographic changes. Group II was further divided into group IIA (9 patients, 5.6%) with permanent electrocardiographic changes, group IIB (14 patients, 8.8%) with transitory electrocardiographic changes, and group IIC (11 patients, 6.9%) with changes appearing only on the final electrocardiogram. Left ventricular ejection fractions remained normal in the entire population studied and did not differ among groups. CONCLUSION: The indeterminate form of Chagas' disease clearly represents a benign condition with a favorable long-term prognosis. Although some patients develop electrocardiographic changes, left ventricular systolic function is well preserved.

An analysis of electrocardiographic criteria for determining left ventricular hypertrophy

OBJECTIVE: To determine the most sensitive criterion for the detection of left ventricular hypertrophy according to echocardiographically defined left ventricular mass. METHODS: The Sokolow-Lyon voltage, Sokolow-Lyon-Rappaport, Cornell voltage duration product, White-Bock, and Romhilt-Estes point scoring criteria were compared with left ventricular mass index, corrected for body surface, obtained from the echocardiograms of 306 outpatients (176 females, 130 males), of all age groups. RESULTS: The Cornell voltage duration product criteria index had the greatest sensitivity in women (54.90%), and the Sokolow-Lyon-Rappaport index was most sensitive in men (73.53%). When applied to men at the same voltage amplitude (20mm) as that in women, the Cornell index showed increased sensitivity relative to the conventional index (28mm) of 67.65% (P<=0.01) and a sensitivity similar to that of the Sokolow-Lyon-Rappaport index, with higher specificity (P<=0.01). The White-Bock and Romhilt-Estes criteria were the least sensitive in men and women, despite their high specificity. The electrocardiographic criteria were more efficient when dilatation predominated over left ventricular hypertrophy. CONCLUSION: The Cornell index had greater sensitivity in women, and the Sokolow-Lyon-Rappaport index was more sensitive in men. When applied to men at the same voltage amplitude as that of women, the Cornell index had an increase in sensitivity similar to that of the Sokolow-Lyon-Rappaport index.

Primary coronary angioplasty in a nonagenarian

A woman aged 98 years entered the tertiary hospital service with a picture of acute myocardial infarction of the extensive anterior wall, which began 4 hours earlier. Due to the large myocardial risk area suggested by the electrocardiogram, the patient was taken to the hemodynamics laboratory for the performance of emergency coronary arteriography, which revealed occlusion in the proximal third of the anterior descending artery. Primary angioplasty followed by stent grafting was successfully performed. The patient had a satisfactory evolution (Killip I) and was discharged from the hospital on the seventh postinfarction day. We discuss here aspects of thrombolysis and coronary percutaneous interventions in the aged.