RESUMO
OBJECTIVES: This study investigated prediction of arrhythmic events by the signal-averaged electrocardiogram (ECG) and programmed stimulation in patients with nonischemic dilated cardiomyopathy. BACKGROUND: Risk stratification in patients with nonischemic dilated cardiomyopathy remains controversial. METHODS: Eighty patients with nonischemic dilated cardiomyopathy and spontaneous nonsustained ventricular tachycardia underwent signal-averaged electrocardiography (both time-domain and spectral turbulence analysis) and programmed stimulation. All patients were followed up for a mean of 22 +/- 26 months. RESULTS: Sustained monomorphic ventricular tachycardia was induced in 10 patients (13%), who all received amiodarone. The remaining 70 patients were followed up without antiarrhythmic therapy. Of the 80 patients, 15% had abnormal findings on the time-domain signal-averaged ECG, and 39% had abnormal findings on spectral turbulence analysis. Time-domain signal-averaged electrocardiography had a better predictive accuracy for induced ventricular tachycardia than spectral turbulence analysis (88% vs. 66%, p < 0.01). During follow-up, there were 9 arrhythmic events (5 sudden deaths, 4 spontaneous ventricular tachycardia/fibrillation) and 10 nonsudden cardiac deaths. Cox regression analysis showed that no variables predicted arrhythmic events or total cardiac deaths. The 2-year actuarial survival free of arrhythmic events was similar in patients with or without abnormal findings on the signal-averaged ECG or induced ventricular tachycardia. CONCLUSIONS: In patients with nonischemic dilated cardiomyopathy, 1) there is a strong correlation between abnormal findings on the time-domain signal-averaged ECG and induced ventricular tachycardia, but both findings are uncommon; and 2) normal findings on the signal-averaged ECG, as well as failure to induce ventricular tachycardia, do not imply a benign outcome.
Assuntos
Arritmias Cardíacas/etiologia , Estimulação Cardíaca Artificial , Cardiomiopatia Dilatada/complicações , Eletrocardiografia , Taquicardia Ventricular/complicações , Análise Atuarial , Adulto , Idoso , Arritmias Cardíacas/fisiopatologia , Arritmias Cardíacas/prevenção & controle , Cardiomiopatia Dilatada/fisiopatologia , Cardiomiopatia Dilatada/terapia , Fatores de Confusão Epidemiológicos , Morte Súbita Cardíaca/etiologia , Eletrocardiografia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Processamento de Sinais Assistido por Computador , Análise de Sobrevida , Taquicardia Ventricular/fisiopatologia , Taquicardia Ventricular/terapiaRESUMO
In order to provide a method for estimation of regional blood flow during hyperthermia, a mathematical model has been developed which employs thermal clearance to measure this physiologic parameter. Limbs of mongrel dogs were heated with 2450 megaHertz microwaves to temperatures of 43 degrees C, 45 degrees C, or 47 degrees C and thermal washout was measured at five minute intervals throughout each treatment period. Calculated blood flow indicates that in response to heat challenge, normal tissue compensates by increasing regional blood flow within the treatment volume. This increase in blood flow continues to a maximum value after which the blood flow begins to decrease. Data indicate that the time for maximum increase in blood flow (induction time) decreases as treatment temperature increases. These induction times were 40 minutes, 25 minutes, and 15 minutes for treatment temperatures of 43 degrees, 45 degrees, and 47 degrees C, respectively. The data also show that the calculated value of peak blood flow is directly related to treatment temperature. Calculated peak blood flow values reached 37.8, 59.0, and 183.0 ml/minute/100 grams of tissue during 43 degrees, 45 degrees, and 47 degrees C, hyperthermia, respectively. It is suggested that a therapeutic advantage could be gained by treating tumors for a specific length of time during which the blood flow in adjacent normal tissues continues to increase. This would take maximum advantage of normal tissue's ability to compensate for increased temperature, and would exploit any decreased ability of tumor tissue to perform this same function.
Assuntos
Temperatura Corporal , Hipertermia Induzida , Músculos/irrigação sanguínea , Animais , Cães , Membro Anterior , Membro Posterior , Matemática , Modelos Biológicos , Neoplasias/irrigação sanguínea , Prognóstico , Fluxo Sanguíneo Regional , Fatores de TempoRESUMO
The value of time-domain and spectral turbulence analyses of the signal-averaged electrocardiogram (SAECG) for predicting induction of sustained monomorphic ventricular tachycardia (VT) was prospectively investigated in 70 patients with idiopathic dilated cardiomyopathy. Sustained VT was induced in 9 patients (13%). The prevalence of abnormal time-domain and spectral analyses was 16 and 37%, respectively. The total predictive accuracy of time-domain and spectral analyses for VT induction was 86 and 67%, respectively (p < 0.01). The predictive accuracy of time-domain and spectral analysis was similar in patients without an intraventricular conduction defect (94 and 84%, respectively). However, the predictive accuracy of time-domain was higher than that of spectral analysis in patients with an intraventricular conduction defect (65 vs 25%; p < 0.05). The poor concordance between spectral analysis and programmed stimulation results was mainly due to the high number of false-positive recordings in the presence of an intraventricular conduction defect (9 of 20 cases). With the use of stepwise discriminant function analysis, an abnormal time-domain SAECG was the only variable predicting the induction of sustained VT (p < 0.0003). In dilated cardiomyopathy, an abnormal time-domain SAECG and induced sustained VT are rare, both time-domain signal-averaged electrocardiography and spectral analysis have a high predictive accuracy for VT induction in patients without an intraventricular conduction defect, and spectral analysis does not improve VT prediction in those with a conduction defect.
Assuntos
Cardiomiopatia Dilatada/complicações , Eletrocardiografia/métodos , Processamento de Sinais Assistido por Computador , Taquicardia Ventricular/etiologia , Análise de Variância , Estimulação Cardíaca Artificial , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Taquicardia Ventricular/diagnósticoRESUMO
The dural sheath may be transected in the course of a posterior thoracic procedure. If air is introduced into the subarachnoid space, a cranial nerve palsy may result. Computed tomographic scanning establishes the diagnosis. The condition resolves without treatment.
Assuntos
Diplopia/etiologia , Histiocitoma Fibroso Benigno/radioterapia , Pneumocefalia/etiologia , Neoplasias Torácicas/radioterapia , Cirurgia Torácica/efeitos adversos , Humanos , Complicações Intraoperatórias , Masculino , Pessoa de Meia-IdadeRESUMO
The haemopoietic cell composition of fetal liver, spleen and thymus was studied in human aborted fetuses of 12-22 weeks gestation. Erythroid cells were present primarily in liver and to a lesser extent in spleen. Orthochromatic normoblasts were the predominant erythroid component. Lymphoid cells were seen primarily in the thymus and to a lesser extent in the spleen. There were few granulocytic and megakaryocytic cells in all these organs. A few primitive haemopoietic cells (Haemocytoblasts) were identified only in liver. These observations indicate that during mid-fetal life (12-22 weeks) the liver contributes primarily to erythropoiesis, the thymus to lymphopoiesis, the spleen to both, and that there is a lack of granulopoiesis and megakaryopoiesis at these sites.
Assuntos
Células-Tronco Hematopoéticas/citologia , Fígado/embriologia , Baço/embriologia , Timo/embriologia , Hematopoese/fisiologia , Humanos , Fígado/citologia , Baço/citologia , Timo/citologiaRESUMO
A non-linear equation of the type log w - 0.008 h = a - be-kl for weight (w) and height (h) of 1177 infants and pre-school children from the Rural Health Centre area in Ballabhgarh was fitted by modified Guass-Newton Method using BMDP 03R program. On applying the non-linear model to the data of the present study it was found that the curve was a good fit in both sexes and also in all nutritional groups. The value of 'a' (the nutritional index) was almost the same in boys and girls but it was higher in case of children with normal nutrition (0.37) and lower in children with malnutrition (0.34 in Grade I, 0.32 in Grade II and 0.28 in Grades III & IV). The exponential term 'k' (index of maturation) was higher in boys compared to that of girls and higher in those with normal nutrition than with malnutrition. It was found that the rate of decay of the exponential term was slower in those with malnutrition compared to those with normal nutrition. While no difference was observed in the asymptotic value i.e., the rate at which infants reach the shape of older children, between boys and girls with normal nutrition (19 and 20 months respectively), it was delayed by 5 to 8 months in girls compared to boys with malnutrition. In the total sample, the Ehrenberg's index attained the asymptotic value at 20 months in boys and at 35 months in girls and at 27 months in the combined sample.
Assuntos
Estatura , Peso Corporal , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Fatores SexuaisRESUMO
Evaluation was undertaken of the effect of chemotherapeutic drugs on the perioperative morbidity of patients with ovarian malignancy undergoing radical surgery. Twenty patients who had received cytotoxic drugs pre-operatively (group I) were compared with 11 patients in whom radical surgery was the first line of treatment (group II). Pre and post-operative cardiac, pulmonary, renal, hepatic and coagulation functions were compared in both groups, as well as the critical intra- and post-operative events like cardiac pump failure, respiratory dysfunction, rhythm disturbances, blood loss, etc. Demographic data, ASA status, biochemical and haematological parameters and cardiac ejection fractions were comparable in the two groups but patients in group I had significantly higher left ventricular end diastolic dimensions (P < 0.01). A higher number of patients in group I had pre-operative respiratory and coagulation factor abnormalities but critical intra- and post-operative events in both groups were comparable. The surgical time was significantly (P < 0.01) longer in group I (5.5 +/- 2.5 h) as compared to group II (4.5 +/- 1.5 h). One patient with extensive tumour spread and pre-operatively deranged coagulation profile (group I) died of disseminated intravascular coagulation in the post-operative period. It is concluded that patients with advanced ovarian malignancy, treated with cytotoxic drugs are more likely to have pre-operative cardiac, respiratory and coagulation abnormalities, which should be managed by thorough pre-operative evaluation and intensive intra- and post-operative monitoring.
Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Ovarianas/cirurgia , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Adulto , Terapia Combinada , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias Ovarianas/tratamento farmacológico , Estudos ProspectivosRESUMO
To determine the efficacy and safety of intermittent intravenous pulse cyclophosphamide in patients of severe systemic lupus erythematosus (SLE), 50 patients having severe/refractory lupus nephritis, vasculitis or neuropsychiatric manifestations were treated with 3 weekly pulses of cyclophosphamide for 6 such pulses. This treatment was found to be associated with significant and sustained improvement during a 2 yr follow up with respect to the mean renal activity score, individual renal parameters (proteinuria, erythrocyturia, and serum creatinine levels), focal neurological manifestations, vasculitic lesions, antinuclear antibody titers, complement component C3, anti-dsDNA antibodies levels and ESR. There was a sustained decrease in the overall mean disease activity score, and the mean daily dose of prednisolone (pretreatment 32.62 mg daily to 3.75 mg daily after 24 months). There was a significant decline in the percentage and absolute B cell count after 7, 14 and 21 days of this treatment. Effect on other lymphocyte subsets (CD3+, CD4+ and CD8+) was not marked. Pulse cyclophosphamide could therefore be an effective and less toxic form of treatment in patients with SLE having severe lupus nephritis, focal neurological lesions or vasculitis.
Assuntos
Ciclofosfamida/uso terapêutico , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Adolescente , Adulto , Criança , Ciclofosfamida/administração & dosagem , Esquema de Medicação , Feminino , Humanos , Infusões Intravenosas , Lúpus Eritematoso Sistêmico/complicações , Nefrite Lúpica/complicações , Nefrite Lúpica/tratamento farmacológico , Masculino , Fatores de TempoRESUMO
BACKGROUND: The crown-rump length is conventionally used to determine the age of human abortuses. However, it is not reliable as it is dependent on the positioning of the conceptus. We compared this with the biparietal diameter and foot length for determining the gestational age. METHODS: Different measurements, commonly used to assess gestational age, were measured in 146 human abortuses for which an accurate obstetric history could not be elicited. Measurements taken were crown-rump length, biparietal diameter and foot length. These were correlated with the observations at antenatal examinations before finalizing the approximate age. RESULTS: Multiple regression analysis of the data indicated that of the three measurements, the biparietal diameter was the most reliable for determining foetal gestational age between 8 and 26 weeks. The age determined with the biparietal diameter correlated well with that of abortuses with an accurate obstetric history. CONCLUSION: The biparietal diameter of a human foetus may be used to determine its age if the obstetric history regarding the period of gestation is vague or not available.
Assuntos
Antropometria , Desenvolvimento Embrionário e Fetal/fisiologia , Feto/anatomia & histologia , Idade Gestacional , Aborto Induzido , Feminino , Humanos , Índia , Recém-Nascido , Gravidez , Primeiro Trimestre da Gravidez , Segundo Trimestre da Gravidez , Valores de ReferênciaRESUMO
Ehrenberg's Law-like relationship between height and weight [log (w) = ah + b] was applied to a group of public school and Govt. school children in New Delhi. It was found that the model log (w) = 0.8 h + 0.4 was comparatively a good fit for public school children and the model log (w) 0.8 h + 0.35 for Govt. school children. On fitting the model to the sample data it was found that the value of 'a' was 0.8, with some minor variation in the second decimal point and the value of 'b' was 0.39 & 0.36 respectively for public school boys and girls and 0.32 & 0.29 respectively for Govt. school boys & girls. These results corroborates with the findings of the earlier studies that the intercept constant 'b' in the Law-like relationship equation is influenced by the nutrition of children. This model is recommended because of its simplicity and practical usefulness using only already available information.
Assuntos
Estatura , Peso Corporal , Modelos Biológicos , Estado Nutricional , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Índia/epidemiologia , Modelos Logísticos , MasculinoRESUMO
PURPOSE: There are a few seroepidemiological studies reported on human metapneumovirus (hMPV) as hMPV was only discovered in the year 2001. This respiratory virus has been reported to be ubiquitous and associated with respiratory tract infections in all age groups. The present study aimed at determining the prevalence of antibodies to hMPV in children and adults of 1 month to 55 years of age. MATERIALS AND METHODS: Serum samples from 100 study subjects were tested for hMPV antibody by an in-house ELISA system that used hMPV-infected cell lysate antigen. RESULT: The prevalence of antibody to hMPV was lowest in children less than 5 years of age (60%) and increased throughout age to > 80%. Similarly, geometric mean titres were 1:180 in children less than 5 years of age and reached a peak of 1:419 in adults over 35 years of age. CONCLUSION: The results show that hMPV infection is acquired early in life and re-infection in later life may maintain the seroprevalence and antibody levels in adult population.
Assuntos
Anticorpos Antivirais/sangue , Metapneumovirus/isolamento & purificação , Infecções por Paramyxoviridae/epidemiologia , Adolescente , Adulto , Fatores Etários , Criança , Pré-Escolar , Ensaio de Imunoadsorção Enzimática , Humanos , Índia/epidemiologia , Lactente , Metapneumovirus/imunologia , Pessoa de Meia-Idade , Infecções por Paramyxoviridae/virologia , Estudos Soroepidemiológicos , Adulto JovemRESUMO
To assist in the prediction of variceal bleeding we examined 12 clinical, endoscopic and haemodynamic variables in 126 patients with portal hypertension (72 bleeders and 54 non-bleeders). Multiple regression and discriminant analysis were utilised for 101 patients. Stepwise regression among the 12 variables explained only 54% of the variability existing between bleeders and non-bleeders. Six of the 12 variables accounted for 51% of the total bleeder/non-bleeder variability. A predicting equation was evolved [Yp = -0.60 + 0.19 X1 (colour of varices) + 0.16 X2 (cherry red spots) + 0.03 X3 (red wale, markings) + 0.01 X4 (haematocystic spots) + 0.15 X5 (Conn's grading of variceal size) + 0.03 X6 (intravariceal pressure)]. Of the six variables used, variceal size indicated 35%, and intravariceal pressure accounted for 12%, of the explained variability between bleeders and non-bleeders. The presence of the three red colour signs and the colour of the varices accounted for only 3% and 1% respectively of the total explained variation. Using the discriminant function analysis, we were able to correctly identify 85% of the bleeders and 81% of the non-bleeders. Additional studies are required to detect the variables responsible for the unexplained variability (46%) between bleeders and non-bleeders.
Assuntos
Varizes Esofágicas e Gástricas/complicações , Hemorragia Gastrointestinal/etiologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Análise Discriminante , Varizes Esofágicas e Gástricas/patologia , Varizes Esofágicas e Gástricas/fisiopatologia , Esofagoscopia , Feminino , Hemodinâmica , Humanos , Hipertensão Portal/complicações , Lactente , Hepatopatias/patologia , Masculino , Pessoa de Meia-Idade , Pressão , Análise de RegressãoRESUMO
Twelve patients with adenocarcinoma of the pancreas and two patients with carcinoma of the extrahepatic biliary tree received combined therapy with 125I implant, precision high-dose (PHD) photon external beam therapy, and systemic 5-fluorouracil (5-FU). The 125I implant delivered 120 to 210 Gy (median 140 Gy). PHD external beam therapy was given with high-energy photons (10, 15 or 45 meVp) and was initiated 4 to 6 weeks postimplant. A dose of 48.6 to 63 Gy was delivered over 5.5 to 7 weeks in 1.8 Gy increments. Six patients received 5-FU, 500 mg/m2 via weekly intravenous bolus injection. No patient was lost to follow-up (range, 3.5-57 months). Acute postoperative morbidity included pancreatic fistula in two patients and gastrointestinal tract bleeding, pulmonary embolism, and cholangitis in one patient each. No patient died of radiation complications. Median survival of the patients with pancrease cancer was 15 months. One patient is alive at 41 months with hepatic metastasis. Satisfactory palliation was observed in patients with pancreas cancer treated with 125I interstitial implant followed by PHD external beam photon therapy and 5-FU. Patient survival did not seem superior to that of patients treated with PHD external beam therapy +/- chemotherapy, a less morbid procedure. Two cases of bile duct cancer treated in similar fashion are presented.
Assuntos
Adenocarcinoma/terapia , Neoplasias dos Ductos Biliares/terapia , Neoplasias Pancreáticas/terapia , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/radioterapia , Idoso , Neoplasias dos Ductos Biliares/tratamento farmacológico , Neoplasias dos Ductos Biliares/radioterapia , Braquiterapia , Feminino , Fluoruracila/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/radioterapia , Dosagem RadioterapêuticaRESUMO
41 (38 males, 3 females) patients with aplastic anemia received fetal liver infusion (FLI) from 74 abortuses with gestation periods of 8-32 (Median(M)-16) weeks and cell dose of 0.004-11.1 x 10(8) (M-2.3 x 10(8)) from September, 1976 until November, 1987. 35 persons received single FLI; those with recurrence or no response received two or more FLI. 8 received two; 7, three; 2, four; and 1, six FLI. There was a slow and incomplete autologous hematopoietic improvement in 40% and expected survival of 52% at 1 year, 45% at 2 yr, and 37% at 5 yr (Kaplan Meier estimate). There was rise in fetal hemoglobin (Hb), 0-15.7%, (M-3.5) among responders in 3-20 (M-6) months. Patients who survived for more than 12 months had, on average, a longer duration of disease (4 months or more), and higher granulocyte and platelet counts. Statistically, however, these differences were not significant. Reticulocyte count was significantly lower in those who survived beyond 12 months. 1 patient developed acute undifferentiated leukemia 3 yr post-FLI. The study indicates that fetal liver infusion is likely to benefit about 40% of individuals suffering from severe aplastic anemia. Longer surviving patients, however, may be at risk of developing clonal diseases.
Assuntos
Anemia Aplástica/terapia , Hematopoese , Fígado/embriologia , Adolescente , Adulto , Idoso , Anemia Aplástica/sangue , Plaquetas/patologia , Criança , Feminino , Transplante de Tecido Fetal/métodos , Granulócitos/patologia , Humanos , Cariotipagem , Masculino , Pessoa de Meia-IdadeRESUMO
A prospective study was conducted to compare the results of long-term endoscopic variceal sclerotherapy in patients with different aetiologies of portal hypertension. A total of 404 consecutive patients were included. There were 234 patients with hepatic cirrhosis, 83 with non-cirrhotic portal fibrosis (NCPF) and 87 with extrahepatic portal venous obstruction (EHO). The mean follow-up for patients with cirrhosis, NCPF and EHO was 25, 37 and 28 months. A total of 73 (31%) patients with cirrhosis, 19 (23%) with NCPF and 10 (11.5%) with EHO rebled (P less than 0.05) on follow-up, prior to eradication of varices. Irrespective of the aetiology, 40 (17%) patients of Child's A class, 42 (33%) of Child's B and 20 (50%) of Child's C class rebled (P less than 0.01). The median bleeding free period (BFP) was longer (P less than 0.05) in patients with EHO than in cirrhotics. Patients in Child's A class had significantly longer BFP than those in Child's B, and the latter had a longer BFP than those in Child's C class (P less than 0.01). The probability of 7-year survival was also better with EHO (97.5%) and NCPF (73.6%) than cirrhotics (41%). Survivals in patients with EHO and NCPF were comparable (P less than 0.1). Similarly 7-year survival irrespective of aetiology in Child's A patients (90.7%) was longer than in Child's B (28.8%), and longer in Child's B than Child's C patients (0%). Success of eradication was greater (P less than 0.05) in EHO (92%) and NCPF (87%) than cirrhotic patients (75%).(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Varizes Esofágicas e Gástricas/terapia , Hemorragia Gastrointestinal/terapia , Hipertensão Portal/complicações , Cirrose Hepática/complicações , Escleroterapia , Adulto , Varizes Esofágicas e Gástricas/etiologia , Varizes Esofágicas e Gástricas/mortalidade , Feminino , Hemorragia Gastrointestinal/etiologia , Hemorragia Gastrointestinal/mortalidade , Humanos , Masculino , Polidocanol , Polietilenoglicóis/uso terapêutico , Estudos Prospectivos , Soluções Esclerosantes/uso terapêutico , Resultado do TratamentoRESUMO
In India 50% of patients with gastrointestinal bleeding bleed from esophageal varices. Causes of portal hypertension includes hepatic cirrhosis, non-cirrhotic portal fibrosis and extrahepatic portal obstruction. Endoscopic sclerotherapy is the treatment of choice to control continued active bleeding. Immediate hemostasis was not influenced by the etiology of portal hypertension. However, rebleeding episodes were lower, in extrahepatic portal vein obstruction than non-cirrhotic portal fibrosis and cirrhotic patients. Child's status significantly influenced recurrence of bleeding and mortality which was lower in child's A than B and lower in B than C irrespective of etiology. Results of long term sclerotherapy were also influenced by the etiology of portal hypertension and hepatic functional status. Sclerotherapy was most effective in patients of (EHO), than (NCPF) followed by cirrhosis of the liver.
Assuntos
Varizes Esofágicas e Gástricas/terapia , Hemorragia Gastrointestinal/terapia , Hipertensão Portal/etiologia , Escleroterapia , Distribuição de Qui-Quadrado , Endoscopia do Sistema Digestório , Varizes Esofágicas e Gástricas/etiologia , Varizes Esofágicas e Gástricas/fisiopatologia , Hemorragia Gastrointestinal/etiologia , Humanos , Hipertensão Portal/complicações , Hipertensão Portal/fisiopatologia , Índia , Fígado/fisiopatologia , Análise de SobrevidaRESUMO
The predictive accuracy of time-domain (TD) late potential analysis of the signal-averaged electrocardiogram in postmyocardial infarction (MI) is limited by the high incidence of false positives in inferior MI. However, frequency-domain spectral turbulence (ST) analysis suffers from a high incidence of false positives, especially in anterior MI. A prospective study was conducted of 262 patients with acute MI to investigate the hypothesis that combined TD and ST analyses of the signal-averaged electrocardiogram could improve its predictive accuracy for serious arrhythmic events in the post-MI period. Abnormal TD criteria were RMS40 less than 25 microV at 25 Hz plus RMS40 less than 16 microV at 40 Hz, and abnormal ST criteria were a turbulence score of 3 or 4. Seventeen patients had arrhythmic events during 10.5 +/- 2.4 months of follow-up evaluation (13 sudden cardiac death judged to be due to arrhythmia and 4 nonfatal sustained ventricular tachycardia). The total predictive accuracy of combined TD and ST (92%) was higher than TD (87%), whereas ST had the lowest total predictive accuracy of 78%. The negative predictive accuracy of all three analyses was high (96-97%). However, the positive predictive accuracy of TD (28%) was higher than ST (14%). Combined TD and ST significantly improved the positive predictive accuracy of the test to 35% in the total group and to 40% in patients with first anterior or inferior MI. The best results were obtained in patients with first anterior MI, where the positive predictive accuracy of combined analysis was 50%.
Assuntos
Arritmias Cardíacas/diagnóstico , Eletrocardiografia , Infarto do Miocárdio/complicações , Processamento de Sinais Assistido por Computador , Arritmias Cardíacas/etiologia , Reações Falso-Positivas , Humanos , Valor Preditivo dos Testes , Estudos ProspectivosRESUMO
The value of time-domain and frequency-domain (spectral turbulence) analyses of the signal-averaged electrocardiogram was investigated to predict induced sustained monomorphic ventricular tachycardia (VT). Two groups of patients with spontaneous nonsustained VT and left ventricular ejection fraction less than 50% were enrolled: 70 patients with idiopathic dilated cardiomyopathy (group 1) and 70 patients with ischemic heart disease (group 2). Sustained VT was induced in 9 cases (13%) in group 1 and 16 (23%) in group 2. The prevalence of abnormal time-domain and spectral turbulence analysis was 16 and 37%, respectively, in group 1 and 27 and 51%, respectively, in group 2 (NS). In group 1, the predictive accuracy of time-domain and spectral turbulence analysis for induced VT was 86 and 67%, respectively (P < .01). In group 2, the predictive accuracy of the two techniques for induced VT was, respectively, 79 and 66% (NS). In both groups, the predictive accuracy of time-domain analysis was higher than that of spectral turbulence analysis in patients with intraventricular conduction defect (IVCD): 65 versus 25%, respectively, in group 1 (P < .01), and 81 versus 44%, respectively, in group 2 (P < .05). However, the predictive accuracy of time-domain and spectral analyses was similar in patients without IVCD: 94 versus 84%, respectively, in group 1, and 77 versus 74%, respectively, in group 2. Thus, in patients with dilated cardiomyopathy, (1) the etiology does not affect the predictive accuracy of time and frequency domain and frequency-domain analyses have high predictive accuracy in patients without IVCD; and (3) spectral turbulence analysis does not improve VT prediction in patients with IVCD.