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Biomedical subjects

A Chinaglia

Publications and source records attributed to A Chinaglia.

15 recordsLinked to original sources

QT interval, cardiovascular risk factors and risk of death in diabetes.

A prolonged QT interval is considered an indicator of increased risk of malignant ventricular arrhythmias and/or sudden death. It has been proposed that autonomic neuropathy in diabetes is related to QT interval prolongation and increased mortality rates. Several studies in Type 1 and Type 2 diabetic patients have confirmed the independent relation between prolonged QT interval duration or increased QT interval dispersion and chronic ischemic heart disease. It has been consistently shown that autonomic neuropathy is related to QT interval duration while more controversies exist on the association with QT interval dispersion. In recent years, studies have confirmed the value of QT interval as a predictor of total mortality in both diabetic and non-diabetic subjects. Moreover, several studies have shown a significant relation between QT interval prolongation and cardiovascular disease risk factors. QT interval could be used to stratify the cardiovascular risk in diabetic patients. We still do not know why QT interval is prolonged and how this abnormality leads to death. Nevertheless, QT interval is a simple, low-cost measure, easily obtainable without the need of the patient's compliance and which could help to select patients who need second level diagnostic procedures and strict observation.

Clinical Trials as Topic↗

QT interval prolongation and mortality in type 1 diabetic patients: a 5-year cohort prospective study. Neuropathy Study Group of the Italian Society of the Study of Diabetes, Piemonte Affiliate.

OBJECTIVE: The aim of the study was to assess the relationship between QT interval prolongation and mortality in type 1 diabetic patients. RESEARCH DESIGN AND METHODS: Data on survival after 5 years were obtained from 316 of 379 patients (83.3%) who took part in a study on the prevalence of diabetic neuropathy and QT interval prolongation. RESULTS: Mortality at 5 years was 6.32%. Patients who survived were significantly younger (P = 0.04), had a shorter duration of diabetes (P = 0.01), had lower systolic (P = 0.004) and diastolic (P = 0.03) blood pressure levels, and had a shorter QT interval corrected for the previous cardiac cycle length (QTc) (P = 0.000005) than subjects who died. In univariate analysis, patients had a higher risk of dying if they had a prolonged QTc (odds ratio [OR] 20.14 [95% CI 5.7-70.81) or if they were affected by autonomic neuropathy (3.55 [1.4-8.9]). QTc prolongation was the only variable that showed a significant mortality OR in multivariate analysis (24.6 [6.51-92.85]; P = 0.0000004). CONCLUSIONS: This is the first cohort-based prospective study indicating that QTc prolongation is predictive of increased mortality in type 1 diabetic patients.

Adolescent↗

The clinical utility of QT interval assessment in diabetes.

A prolonged (QT) interval is considered an indicator of an increased risk of malignant ventricular arrhythmias and/or sudden death. It has been proposed that autonomic neuropathy in diabetes is related to QT interval prolongation and higher mortality rates. More recently, the interlead difference in QT interval duration has been referred to as QT interval dispersion, which has proven to be predictive of ventricular arrhythmias and mortality in different groups of patients. QT interval duration and dispersion are significantly related, but are not concordant in a substantial number of cases in identifying patients at risk. The prevalence of QT prolongation in Type 1 and Type 2 diabetic (T1 and T2DM) patients is higher than 20%. Several studies in T1 and T2DM patients have confirmed the independent relation between prolonged QT interval duration and increased QT interval dispersion and chronic ischemic heart disease. It has been consistently shown that autonomic neuropathy is related to QT interval duration, while more controversies exist on the association with QT interval dispersion. In recent years 5 studies have been published which confirm the value of QT interval as a predictor of total mortality in diabetic as well as in non-diabetic subjects. Surprisingly, no data exist on the relation between the risk of sudden death and QT interval prolongation in diabetic patients. As corrected QT interval is significantly related to mortality, it could be used to stratify the death risk in diabetic patients, particularly those who are candidates for surgery or kidney and/or pancreas transplantation. We still do not know why QT interval is prolonged and how this abnormality leads to death: however, a simple, low-cost measurement, which is easily obtainable without the need of the patient's compliance, could help select patients who need second level diagnostic procedures and strict observation.

Arrhythmias, Cardiac↗

New diagnostic criteria for infective endocarditis. A study of sensitivity and specificity.

OBJECTIVE: The purpose of this study was to determine the sensitivity and specificity of new criteria proposed by Duke University for case definition of infective endocarditis as compared to the previously accepted Von Reyn criteria. PATIENTS: A total of 143 consecutive suspected cases of infective endocarditis in 137 febrile patients were included. Of these, 69 had infective endocarditis, pathologically proven in 28, but with only a clinical diagnosis in 41. In the remaining 74 cases, the diagnosis of infective endocarditis was rejected after a follow-up of at least 3 months. RESULTS: The sensitivity of Duke's criteria was significantly higher, both when patients with possible infective endocarditis were considered as true-positive (definition 1; 100% vs 69%, P < 0.001) and when possible cases were considered as rejected (definition 2; 76% vs 51%, P < 0.01). Specificity was very high with both criteria: 92% Von Reyn vs 88% Duke (ns) with definition 1 and 99% Von Reyn vs 97% Duke (ns) with definition 2. The overall accuracy of the Duke criteria in the entire population was significantly higher with both definitions (0.94 vs 0.81 definition 1, P < 0.001; 0.87 vs 0.75, P = 0.015 definition 2). CONCLUSION: Duke's criteria for defining infective endocarditis has been shown to be more sensitive than previously adopted criteria, while maintaining a high degree of specificity. Therefore, they must be accepted as a substitute for previous criteria.

Adolescent↗

[Cardiac complications in HIV infections].

UNLABELLED: Cardiological involvement in HIV infection is relatively rare but it presents important clinical aspects that are still open questions. We report our experience with HIV patients who underwent cardiological evaluation, Doppler echocardiography and follow-up. MATERIAL AND METHOD: We selected 127 patients (9%) on the basis of clinical suspicion of heart disease, taking them from the 1398 admitted for HIV infection between 1992 and 1995. Ninety-six patients had AIDS (group A) and 31 were in pre-AIDS phase (group B). The age was 21-52 years: 83 were males, 44 were females and 91% of the patients had been drug addicts. Echocardiography was executed with Hp Sonos 1000 and Sonos 2500 devices. Follow-up was 6-36 months. RESULTS: Ninety-two patients (6.5% on total admitted patients) had heart disease. Thirty-five patients were normal on echocardiography. Other diseases were: pericardial effusion in 38 cases (30%), with CD4+ number significantly lower (p < 0.005); dilated cardiomyopathy in 20 patients (16%), with a low CD4+ number (p < 0.005); reversible segmental or diffuse hypokinesia compatible with clinical myocarditis was seen in 11 patients (9%), especially in group A (p < 0.005); infective endocarditis in 17 patients (13%), especially group B (p < 0.005); right ventricular dilatation in 7; discrete right ventricular mass in 3 patients. Sixty-five patients (51%) died during follow-up (group A only). There were 19 cardiac deaths (15%), which represents 1.3% of the total number of patients. Nine of these (47%) were in patients with cardiomyopathy. Total mortality was 85% in patients with dilated cardiomyopathy, 73% in myocarditis cases, 71% in pericarditis cases (especially extracardiac), 66% in right ventricular dilatation cases, 18% in endocarditis cases, 34% in normal cases. CONCLUSIONS: Cardiac complications assume clinical importance, especially in the AIDS phase of HIV infection, but early diagnosis in the pre-AIDS phase is important for treatment. Clinical evaluation and echocardiography are corner-stones of the diagnosis. Prognosis depends especially on the clinical stage of HIV infection and myocardial involvement.

Acquired Immunodeficiency Syndrome↗

Diagnostic value of echocardiography in infective endocarditis: a probabilistic approach.

The high sensitivity and specificity of echocardiography in the diagnosis of infective endocarditis have been well established for a number of years. However, little is known yet about the incremental value of this technique over the clinical and serological findings already available in subsets of patients presenting different initial probabilities in infective endocarditis. In this report, sensitivity and specificity of echocardiography were calculated in 173 consecutive patients with suspected infective endocarditis who underwent echocardiography within 5 days following admission. The echocardiogram was considered positive when Duke major criteria were fulfilled. Infective endocarditis was diagnosed in 88 patients, while other illnesses in the remaining 85. The diagnoses were confirmed retrospectively with a follow-up done after at least 3 months, at surgery or during autopsy. Sensitivity and specificity of the echocardiography in this population were 85 and 97% respectively. The initial probabilities of infective endocarditis in patients with different clinical presentations were taken from a thorough review of the literature available in English and from personal research. The positive predictive value of echocardiography is already high or very high even at low or very low levels of initial probability, and this has a strong impact on clinical decisions. In these situations and with intermediate probabilities, a negative echocardiogram would theoretically rule out the disease. However, this result, if considered alone, calls for a careful reassessment of the entire clinical context. As with any other test, when the initial probabilities of infective endocarditis are highest, the incremental value of echocardiography is poor.

Adolescent↗

Does abnormal QT interval prolongation reflect autonomic dysfunction in diabetic patients? QTc interval measure versus standardized tests in diabetic autonomic neuropathy.

The question as to whether the QTc interval correlates with five cardiovascular tests (deep breathing test, 30/15 ratio test, lying to standing test, cough test, and postural blood pressure test) for the diagnosis of diabetic autonomic neuropathy (DAN) was investigated in 168 (38 Type 1, 130 Type 2) consecutive outpatients (mean age 54.9 +/- 11.2 years). QT interval was measured on an ECG recorded at rest and QTc calculated according to Bazett's formula. The percentage of patients with a QTc greater than 0.440 s was: absent DAN = 11% (n = 7), probable DAN = 7% (n = 4), definite DAN = 23% (n = 12) (p < 0.05), and the mean (+/- SD) QTc values were 0.403 +/- 0.028 s, 0.405 +/- 0.023 s, and 0.421 +/- 0.026 s, respectively. A significant correlation between QTc duration and DAN score of autonomic cardiovascular test results (r = 0.34, p < 0.0001) was observed. The calculated specificity, sensitivity, positive and negative predictive values were 89%, 15%, 70% and 37%, respectively. In conclusion, QTc can be considered as an additional specific test in the assessment of diabetic autonomic neuropathy, but cannot replace the standard battery of cardiovascular tests.

Analysis of Variance↗

Prevalence of QT prolongation in a type 1 diabetic population and its association with autonomic neuropathy. The Neuropathy Study Group of the Italian Society for the Study of Diabetes.

The prevalence of QT prolongation in a large random sample of Type 1 diabetic patients in Piemonte, Italy and its association with autonomic neuropathy were assessed. Three hundred and seventy-nine Type 1 diabetic patients (age 15-59) with (94, DAN+) and without (280, DAN-) autonomic neuropathy and 118 non-diabetic control subjects participated in the study. QT interval was measured on an ECG recorded at rest and QTc calculated according to Bazett's formula. QTc was greater than 0.440 s in 7.6% (95% CI 2.9-12.3) of control subjects, 25.6% (21.0-30.0) of diabetic patients, 30.8% (21.5-40.1) of DAN+, 23.9% (18.9-28.9) of DAN-. QTc was greater than 0.460 s (mean + 2SD of QTc in control subjects) in 11.7% (8.5-14.9) of diabetic patients, 18.1% (10.3-25.9) of DAN+, 9.6% (6.2-13.0) of DAN-. QT was above the 95% upper limit for the control subjects in the plot of measured QT against RR interval in 21.4% (17.3-25.5) of diabetic patients, 26.6% (17.7-35.5) of DAN+, 19.3% (14.7-23.9) of DAN-. No correlation was found between QT interval and age or disease duration. The prevalence of QT prolongation was higher in diabetic patients than in control subjects and in DAN+ than in DAN-.

Adolescent↗

[Torsade de pointes following intravenous infusion of amiodarone].

A case of intravenous amiodarone induced QT-interval prolongation and ventricular arrhythmia of the torsade de pointes type is described: the arrhythmia developed in the presence of hypokalemia. The efficacy of lidocaine in suppressing this type of arrhythmia is reported. The electrophysiologic effects of intravenous and oral amiodarone administration are compared.

Aged↗