Massimo Romano

Asymptomatic transient ST changes during ambulatory ECG monitoring in diabetic patients

The reported higher incidence of painless myocardial infarction in diabetic patients suggests that asymptomatic transient myocardial ischemia may also be frequent in diabetes. To explore this possibility 51 subjects with type II diabetes, aged 43 to 71 years (mean +/- SEM 56 +/- 8), 70 nondiabetic patients with coronary artery disease (mean age 55 +/- 5), and 40 nondiabetic patients without overt coronary disease (age 54 +/- 9) were studied. Thirty-eight of the 51 diabetic patients (74%) had evidence of associated coronary disease and 19 (37%) had evidence of previous myocardial infarction. All subjects underwent continuous 24-hour ambulatory ECG monitoring. In 18 of 51 diabetic patients 93 episodes (73% of the total number) of asymptomatic ST segment changes were recorded; the total number of symptomatic episodes was 36, and they were observed in seven patients (27%). Forty-eight (60%) asymptomatic and 32 symptomatic episodes of significant ST changes were found in nondiabetic patients with coronary artery disease. When patients with previous myocardial infarction were examined separately, asymptomatic episodes of significant ST changes were observed in 10 of 19 diabetic patients and in 5 of 25 nondiabetic patients with coronary artery disease (p less than 0.05). In an additional 28 diabetic patients who underwent exercise stress test, 15 exhibited an abnormal ECG response; however, only five of them (33%) were symptomatic. This study suggests that the incidence of transitory myocardial ischemia, as assessed by ambulatory ECG monitoring and exercise stress test, is higher in type II diabetic patients than in nondiabetic control subjects with coronary artery disease.

Relation between heart rate and QT interval in exercise-induced myocardial ischemia.

The relation between heart rate and QT interval during dynamic upright exercise on a bicycle ergometer was investigated in control subjects (n = 18) and in patients with coronary artery disease (CAD), stable angina on effort, and angiographically documented significant coronary stenoses (n = 23). Both groups had a significant negative linear relation between heart rate and QT, with a higher correlation coefficient in control subjects (r = -0.78) than in patients with CAD (r = -0.64). This response may be a result of the nonhomogeneous response to ischemia in patients with CAD, particularly with regard to the different impact of exercise-induced ischemia. When the 2 regression lines were compared, a flatter slope was found in the CAD group (p less than 0.001) as a consequence of a faster decrease in the QT-increasing rate in control subjects. It is suggested that in control subjects exercise-induced increase in adrenergic tone causes a rapid and relevant decrease in QT-interval duration. In the CAD group, exercise-induced ischemia relatively prolonged the QT interval; this may have been the result of an impairment of myocardium in response to catecholamines release during exercise or the consequence of a direct effect of exercise-induced ischemia prolonging the duration of myocardial tension.

Abnormal systolic time intervals in obesity and their relationship with the amount of overweight

We studied 17 severely obese subjects (age range 26 to 42 years), without hypertension, diabetes mellitus, angina, or clinical signs of heart failure or respiratory disease, and 16 age-matched control subjects. X-teleroentgenographic findings (transverse cardiac diameter and cardiothoracic ratio), blood pressure, and mechanocardiographic parameters were analyzed in both groups. By means of conventional simultaneous recordings of ECG, phonocardiogram, and carotid pulse (100 mm/sec), systolic time intervals were calculated as mean values from 10 beats in the morning. The following comparisons were made by means of analysis of variance: heart rate, preejection period (PEP), rate-corrected PEPI (PEPI), left ventricular ejection time (LVET), and QS2 interval (QS2); the latter two were both corrected for heart rate, respectively, as LVETI and QS2I and the PEP/LVET ratio. Abnormal x-ray data were shown in the obese group along with higher values for heart rate, PEP, PEPI, and PEP/LVET and a shorter LVETI; there were no differences in QS2I or blood pressure. There was a correlation between the amount of overweight and, respectively, transverse cardiac diameter (r = 0.84), heart rate (r = 0.69), PEP (r = 0.49), PEPI (r = 0.59), LVETI (r = -0.61), and PEP/LVET ratio (r = 0.72). A correlation was also found between transverse cardiac diameter and PEP/LVET (r = 0.67). We conclude, therefore, that abnormalities in the mechanocardiographic parameters are related to cardiac enlargement, suggesting a preclinical cardiac dysfunction secondary to chronic cardiocirculatory overload in severe obesity. Thus systolic time intervals appear to be affected by preclinical abnormalities of cardiac performance in these subjects.

Added value of CT colonography after a positive conventional colonoscopy: impact on treatment strategy

BackgroundConventional colonoscopy (CC) requires an experienced operator to avoid technical or interpretative errors, and an endoscopic error rate of 14% for tumor localization has been reported. We evaluated the impact of computed tomographic colonography (CTC) on surgical treatment strategy in patients with CC reported as having colorectal neoplasm.MethodsFifty-three patients testing positive for colorectal neoplasm on CC underwent CTC: 32 patients had CC in our hospital (group A) and 21 had CC in area hospitals (group B). All CTC procedures were performed with a multidetector CT system. The results of CTC and CC were compared with that of surgery. The preoperative surgical planning evaluated on the basis of CC and CTC was compared with the actual surgical approach, and the percentage of patients in whom CTC modified the treatment strategy suggested by CC was calculated.ResultsCTC changed the treatment strategy in four of 53 patients (7.5%) in whom CC showed technical or interpretative errors. Group analysis showed that CTC did not influence the surgical management in any patient in group A but did affect treatment strategy in four of 21 patients (19%) in group B. The effect of CTC on treatment strategy between groups was statistically significant (p<0.05). CTC identified five adenomas and three adenocarcinomas localized proximally to an impassable stenosis.ConciusionCTC can be used to reevaluate the findings of a positive CC and can indicate a more correct therapeutic approach in patients with colorectal neoplasms who are candidates for surgery.