Body surface potential maps were recorded from 140 chest leads in 25 patients affected by the idi... more Body surface potential maps were recorded from 140 chest leads in 25 patients affected by the idiopathic long QT syndrome (LQTS) and in 25 healthy control subjects matched for age and sex. Potential time integrals of the QRST and ST-T intervals were calculated at each lead point and displayed as isointegral (ISOI) maps. The main abnormalities noted on the QRST and ST-T ISOI maps were one area of negative values larger than normal in the right anterior and inferior thorax and a complex multipeak distribution of the integral values. At least one abnormality was present in 19 (76%) of the patients with LQTS and four (16%) of the control subjects (p <.001). Each ISOI map was also represented as a weighted sum of nine fundamental components (eigenvectors) to detect and quantitate the nondipolar content. The percent contribution of the nondipolar eigenvectors (all eigenvectors beyond the third) was significantly higher in the LQTS group than in the control group (p <.005). Specifica...
Echo-dipyridamole test is an useful tool for non-invasive demonstration of inducible myocardial i... more Echo-dipyridamole test is an useful tool for non-invasive demonstration of inducible myocardial ischemia in patients with coronary artery disease, its sensitivity being consistently higher as compared with classic exercise stress testing. However, in patients with single vessel who often perform a normal or borderline stress test, even the sensibility of echo-dipyridamole test is comparatively reduced. In 19 patients with clinically suspected angina (effort-related in 4, at rest in 8, mixed in 7) and normal exercise stress test, standard echo-dipyridamole test was performed. Thereafter, rapid atrial pacing, a procedure associated with a sharp increase of myocardial oxygen consumption, was performed by means of a transoesophageal catheter during the proceeding 5 min and during 4 min of repeated dipyridamole 0.56 mg/kg infusion. Standard echo-dipyridamole test induced ventricular wall motion abnormalities in 3 patients (one with borderline exercise stress test), whereas repeated pacin...
Purpose of our investigation was to ascertain whether the electrocardiographic mapping of the ant... more Purpose of our investigation was to ascertain whether the electrocardiographic mapping of the anterior thoracic wall can provide more precise information on the extent of an anterior myocardial infarction (MI) than the 12 conventional leads do. Thirty-seven patients were studied 1 to 72 months after an acute MI of the anterior wall. All patients underwent left heart catheterization which included selective coronary arteriography and left ventriculography, to evaluate the indication for surgery. Electromaps were obtained by means of 71 Ag-AgCl electrodes located at regular intervals on the thoracic wall (between the right midclavicular line and the left posterior axillary line). The following parameters were considered: total number of Q waves, R waves and ST elevations greater than or equal to 0.05 mV (NQ, NR, NST); the sum of Q, R and ST voltages (sigma Q, sigma R, sigma ST); the sum of Q-wave and R-wave areas (sigma aQ, sigma aR). The electrocardiographic data were correlated with...
Amrinone is a nonadrenergic, nonglycosidic agent with combined positive inotropic and vasodilator... more Amrinone is a nonadrenergic, nonglycosidic agent with combined positive inotropic and vasodilator properties. To determine its clinical and hemodynamic effects we treated 14 patients (12 men and 2 women ranging in age from 36 to 78 years, mean 56) with severe chronic heart failure (New York Heart Association functional class IIIa or IVa) not controlled by conventional therapy. Drug administration: 1 mg/Kg intravenous bolus followed by infusion of 10 mcg/Kg/min over 24 hours; in 11 patients, upon termination of long term infusion, oral therapy was begun (100 mg tid) for a period of four weeks. After bolus and during infusion dyspnea, pulmonary and jugular vein congestion, hepatomegaly rapidly improved, and increase of diuresis was noted. All patients responded with a substantial reduction in central venous pressure (CVP 9.64 +/- 5.96----4.79 +/- 5.66 mmHg, P less than 0.01), wedge pressure (WP 26.3 +/- 4.6----19.00 +/- 4.66 mmHg, P less than 0.01), pulmonary and systemic vascular res...
International journal of clinical pharmacology, therapy, and toxicology, 1988
To evaluate the effects of the chronic administration of the fixed combination slow-release, oxpr... more To evaluate the effects of the chronic administration of the fixed combination slow-release, oxprenolol 160 mg and chlorthalidone 20 mg on left ventricular hypertrophy, ten hypertensive out-patients, with left ventricular hypertrophy documented by left ventricular mass index (LVMI) greater than 130 g/m2, were studied. After a two-week placebo period, patients were given the study medication, once daily for six months. Blood pressure and heart rate were measured, 24 h after-dosing, at the end of placebo and thereafter every month. A m-mode echocardiographic examination was performed at the end of the placebo period, after 1 month of active treatment and at the end of the study. In comparison with placebo, the study medication induced a significant reduction (p less than 0.01) of systolic and diastolic blood pressure, 24 h after dosing, after 1 month of treatment (from 181.0 +/- 18.5/108.5 +/- 12.0 to 146.5 +/- 10.8/94.0 +/- 7.7 mmHg), and this reduction was maintained until the end o...
To assess acute hemodynamic effects and exercise capacity of an intravenously administered single... more To assess acute hemodynamic effects and exercise capacity of an intravenously administered single dose of captopril and to compare the acute response with chronic variation in hemodynamic and functional parameters after long-term oral administration, (in order to determine the profile of responders and non-responders) we studied 12 patients with chronic congestive heart failure due to primary dilated cardiomyopathy (11 pts) and ischemic heart disease (1 pt). Hemodynamic response was assessed using transthoracic electric impedance with cardiac output measurement. The exercise capacity was determined using multistage bicycle ergometer symptoms limited stress test. The hemodynamic and functional evaluation--resting cardiac output, exercise capacity (Ex. Dur.) and cardiac output rise at maximum workload (% CO)--were investigated at first as a control; after i.v. captopril administered in 10 min (25 mg) (acute); after captopril per os (25-75 mg for 30 days) (chronic) and after 5 days of ...
Evidence for the relation between disparities of ventricular recovery times and arrhythmias has b... more Evidence for the relation between disparities of ventricular recovery times and arrhythmias has been provided by experimental studies. An index of local disparities of the repolarization is based on the detection of nondipolar components of the QRST integral distribution. The aim of our study was to determine the nondipolar content of QRST integral maps by applying the principal component analysis. We obtained maps from 140 ECG leads in 3~0 healthy controls (C) and in 70 patients with an old myocardial infarction: 8 of these had had episodes of sustained ventricular tachycardia (VT). Each map was represented as a weighted sum of 9 fundamental components to quantitate the nondipolar content. The percent contribution of the nondipolar components Call components beyond the third) was significantly higher in pts (7.8+5.7) than in C {4.1+2.2%). High values (exceeding normal mean +ISD) of the percent nondipolar content were found in 4/30 C (13%), in 28/62 pts without VT (45%} and in 7/8 VT pts (88%1. The high nondipolar content of QRST map in VT pts suggests the presence of local disparities in recovery duration and it might be considered a useful noninvasive marker of susceptibility to malignant arrhythmias.
can improve the stability, as can the application of regularization techniques in computing the i... more can improve the stability, as can the application of regularization techniques in computing the inverse solution. This paper demonstrates the improvements to stability that can be achieved in these ways. The correctness of a solution is as impo~ant as its stability, but relatively few studies have been made that can provide direct confirmation of inverse solutions. By reference to previous physiological studies of the cardiac activation sequence, and by the use of direct epicardial measurements using small numbers of implanted pacing electrodes following surgery in humans, qualitative indications of the correctness of the inverse solution are also demonstrated.
Body surface potential maps were recorded from 140 chest leads in 25 patients affected by the idi... more Body surface potential maps were recorded from 140 chest leads in 25 patients affected by the idiopathic long QT syndrome (LQTS) and in 25 healthy control subjects matched for age and sex. Potential time integrals of the QRST and ST-T intervals were calculated at each lead point and displayed as isointegral (ISOI) maps. The main abnormalities noted on the QRST and ST-T ISOI maps were one area of negative values larger than normal in the right anterior and inferior thorax and a complex multipeak distribution of the integral values. At least one abnormality was present in 19 (76%) of the patients with LQTS and four (16%) of the control subjects (p less than .001). Each ISOI map was also represented as a weighted sum of nine fundamental components (eigenvectors) to detect and quantitate the nondipolar content. The percent contribution of the nondipolar eigenvectors (all eigenvectors beyond the third) was significantly higher in the LQTS group than in the control group (p less than .005...
We assessed the accuracy of criteria for diagnosing an inferior myocardial infarction from body p... more We assessed the accuracy of criteria for diagnosing an inferior myocardial infarction from body potential maps. Body surface potential maps were recorded from 140 lead points on the entire chest surface in three groups of subjects: group A consisted of 15 patients with an old inferior myocardial infarction and typical electrocardiographic signs of necrosis; group B consisted of 15 patients with an old inferior myocardial infarction, but without electrocardiographic signs of necrosis (inferior myocardial infarction was documented during the acute phase); group C consisted of 30 healthy controls. In each subject body surface potential distributions were examined every 2 msec of the QRS complex. Moreover, the potential-time integrals relating to three intervals (QRS, the first 20 and the first 40 msec of the QRS complex) were calculated at each lead point and transferred to diagrams representing the thoracic surface explored (isointegral maps). For each time interval, the mean isointegral map obtained from group C subjects was subtracted from the isointegral map of each patient. The value obtained at each lead point was then divided by the standard deviation of the normal values for that point; the resulting values indicating the standardized differences from normal values were transferred to another map (deviation index isointegral map, DI map). We considered a reliable index of inferior myocardial infarction an area where the time-integral values were at least 2 SD lower than normal, in the inferior half of the thorax. A number of variables relative to instantaneous potential distribution and to isointegral maps were considered. The DI maps of the first 40 msec of QRS gave the most accurate criteria; in fact, an area of negative values 2 SD lower than normal was found in all group A patients and in 11 out of 15 group B patients (sensitivity 100% in group A, 73% in group B and specificity, 83%). Thus our results indicate that body surface potential maps have greater diagnostic information content than the 12 standard electrocardiographic leads and demonstrate the usefulness of the time integral analysis of body surface potentials for diagnostic interpretation.
Body surface potential maps were recorded from 140 chest leads in 25 patients affected by the idi... more Body surface potential maps were recorded from 140 chest leads in 25 patients affected by the idiopathic long QT syndrome (LQTS) and in 25 healthy control subjects matched for age and sex. Potential time integrals of the QRST and ST-T intervals were calculated at each lead point and displayed as isointegral (ISOI) maps. The main abnormalities noted on the QRST and ST-T ISOI maps were one area of negative values larger than normal in the right anterior and inferior thorax and a complex multipeak distribution of the integral values. At least one abnormality was present in 19 (76%) of the patients with LQTS and four (16%) of the control subjects (p <.001). Each ISOI map was also represented as a weighted sum of nine fundamental components (eigenvectors) to detect and quantitate the nondipolar content. The percent contribution of the nondipolar eigenvectors (all eigenvectors beyond the third) was significantly higher in the LQTS group than in the control group (p <.005). Specifica...
Echo-dipyridamole test is an useful tool for non-invasive demonstration of inducible myocardial i... more Echo-dipyridamole test is an useful tool for non-invasive demonstration of inducible myocardial ischemia in patients with coronary artery disease, its sensitivity being consistently higher as compared with classic exercise stress testing. However, in patients with single vessel who often perform a normal or borderline stress test, even the sensibility of echo-dipyridamole test is comparatively reduced. In 19 patients with clinically suspected angina (effort-related in 4, at rest in 8, mixed in 7) and normal exercise stress test, standard echo-dipyridamole test was performed. Thereafter, rapid atrial pacing, a procedure associated with a sharp increase of myocardial oxygen consumption, was performed by means of a transoesophageal catheter during the proceeding 5 min and during 4 min of repeated dipyridamole 0.56 mg/kg infusion. Standard echo-dipyridamole test induced ventricular wall motion abnormalities in 3 patients (one with borderline exercise stress test), whereas repeated pacin...
Purpose of our investigation was to ascertain whether the electrocardiographic mapping of the ant... more Purpose of our investigation was to ascertain whether the electrocardiographic mapping of the anterior thoracic wall can provide more precise information on the extent of an anterior myocardial infarction (MI) than the 12 conventional leads do. Thirty-seven patients were studied 1 to 72 months after an acute MI of the anterior wall. All patients underwent left heart catheterization which included selective coronary arteriography and left ventriculography, to evaluate the indication for surgery. Electromaps were obtained by means of 71 Ag-AgCl electrodes located at regular intervals on the thoracic wall (between the right midclavicular line and the left posterior axillary line). The following parameters were considered: total number of Q waves, R waves and ST elevations greater than or equal to 0.05 mV (NQ, NR, NST); the sum of Q, R and ST voltages (sigma Q, sigma R, sigma ST); the sum of Q-wave and R-wave areas (sigma aQ, sigma aR). The electrocardiographic data were correlated with...
Amrinone is a nonadrenergic, nonglycosidic agent with combined positive inotropic and vasodilator... more Amrinone is a nonadrenergic, nonglycosidic agent with combined positive inotropic and vasodilator properties. To determine its clinical and hemodynamic effects we treated 14 patients (12 men and 2 women ranging in age from 36 to 78 years, mean 56) with severe chronic heart failure (New York Heart Association functional class IIIa or IVa) not controlled by conventional therapy. Drug administration: 1 mg/Kg intravenous bolus followed by infusion of 10 mcg/Kg/min over 24 hours; in 11 patients, upon termination of long term infusion, oral therapy was begun (100 mg tid) for a period of four weeks. After bolus and during infusion dyspnea, pulmonary and jugular vein congestion, hepatomegaly rapidly improved, and increase of diuresis was noted. All patients responded with a substantial reduction in central venous pressure (CVP 9.64 +/- 5.96----4.79 +/- 5.66 mmHg, P less than 0.01), wedge pressure (WP 26.3 +/- 4.6----19.00 +/- 4.66 mmHg, P less than 0.01), pulmonary and systemic vascular res...
International journal of clinical pharmacology, therapy, and toxicology, 1988
To evaluate the effects of the chronic administration of the fixed combination slow-release, oxpr... more To evaluate the effects of the chronic administration of the fixed combination slow-release, oxprenolol 160 mg and chlorthalidone 20 mg on left ventricular hypertrophy, ten hypertensive out-patients, with left ventricular hypertrophy documented by left ventricular mass index (LVMI) greater than 130 g/m2, were studied. After a two-week placebo period, patients were given the study medication, once daily for six months. Blood pressure and heart rate were measured, 24 h after-dosing, at the end of placebo and thereafter every month. A m-mode echocardiographic examination was performed at the end of the placebo period, after 1 month of active treatment and at the end of the study. In comparison with placebo, the study medication induced a significant reduction (p less than 0.01) of systolic and diastolic blood pressure, 24 h after dosing, after 1 month of treatment (from 181.0 +/- 18.5/108.5 +/- 12.0 to 146.5 +/- 10.8/94.0 +/- 7.7 mmHg), and this reduction was maintained until the end o...
To assess acute hemodynamic effects and exercise capacity of an intravenously administered single... more To assess acute hemodynamic effects and exercise capacity of an intravenously administered single dose of captopril and to compare the acute response with chronic variation in hemodynamic and functional parameters after long-term oral administration, (in order to determine the profile of responders and non-responders) we studied 12 patients with chronic congestive heart failure due to primary dilated cardiomyopathy (11 pts) and ischemic heart disease (1 pt). Hemodynamic response was assessed using transthoracic electric impedance with cardiac output measurement. The exercise capacity was determined using multistage bicycle ergometer symptoms limited stress test. The hemodynamic and functional evaluation--resting cardiac output, exercise capacity (Ex. Dur.) and cardiac output rise at maximum workload (% CO)--were investigated at first as a control; after i.v. captopril administered in 10 min (25 mg) (acute); after captopril per os (25-75 mg for 30 days) (chronic) and after 5 days of ...
Evidence for the relation between disparities of ventricular recovery times and arrhythmias has b... more Evidence for the relation between disparities of ventricular recovery times and arrhythmias has been provided by experimental studies. An index of local disparities of the repolarization is based on the detection of nondipolar components of the QRST integral distribution. The aim of our study was to determine the nondipolar content of QRST integral maps by applying the principal component analysis. We obtained maps from 140 ECG leads in 3~0 healthy controls (C) and in 70 patients with an old myocardial infarction: 8 of these had had episodes of sustained ventricular tachycardia (VT). Each map was represented as a weighted sum of 9 fundamental components to quantitate the nondipolar content. The percent contribution of the nondipolar components Call components beyond the third) was significantly higher in pts (7.8+5.7) than in C {4.1+2.2%). High values (exceeding normal mean +ISD) of the percent nondipolar content were found in 4/30 C (13%), in 28/62 pts without VT (45%} and in 7/8 VT pts (88%1. The high nondipolar content of QRST map in VT pts suggests the presence of local disparities in recovery duration and it might be considered a useful noninvasive marker of susceptibility to malignant arrhythmias.
can improve the stability, as can the application of regularization techniques in computing the i... more can improve the stability, as can the application of regularization techniques in computing the inverse solution. This paper demonstrates the improvements to stability that can be achieved in these ways. The correctness of a solution is as impo~ant as its stability, but relatively few studies have been made that can provide direct confirmation of inverse solutions. By reference to previous physiological studies of the cardiac activation sequence, and by the use of direct epicardial measurements using small numbers of implanted pacing electrodes following surgery in humans, qualitative indications of the correctness of the inverse solution are also demonstrated.
Body surface potential maps were recorded from 140 chest leads in 25 patients affected by the idi... more Body surface potential maps were recorded from 140 chest leads in 25 patients affected by the idiopathic long QT syndrome (LQTS) and in 25 healthy control subjects matched for age and sex. Potential time integrals of the QRST and ST-T intervals were calculated at each lead point and displayed as isointegral (ISOI) maps. The main abnormalities noted on the QRST and ST-T ISOI maps were one area of negative values larger than normal in the right anterior and inferior thorax and a complex multipeak distribution of the integral values. At least one abnormality was present in 19 (76%) of the patients with LQTS and four (16%) of the control subjects (p less than .001). Each ISOI map was also represented as a weighted sum of nine fundamental components (eigenvectors) to detect and quantitate the nondipolar content. The percent contribution of the nondipolar eigenvectors (all eigenvectors beyond the third) was significantly higher in the LQTS group than in the control group (p less than .005...
We assessed the accuracy of criteria for diagnosing an inferior myocardial infarction from body p... more We assessed the accuracy of criteria for diagnosing an inferior myocardial infarction from body potential maps. Body surface potential maps were recorded from 140 lead points on the entire chest surface in three groups of subjects: group A consisted of 15 patients with an old inferior myocardial infarction and typical electrocardiographic signs of necrosis; group B consisted of 15 patients with an old inferior myocardial infarction, but without electrocardiographic signs of necrosis (inferior myocardial infarction was documented during the acute phase); group C consisted of 30 healthy controls. In each subject body surface potential distributions were examined every 2 msec of the QRS complex. Moreover, the potential-time integrals relating to three intervals (QRS, the first 20 and the first 40 msec of the QRS complex) were calculated at each lead point and transferred to diagrams representing the thoracic surface explored (isointegral maps). For each time interval, the mean isointegral map obtained from group C subjects was subtracted from the isointegral map of each patient. The value obtained at each lead point was then divided by the standard deviation of the normal values for that point; the resulting values indicating the standardized differences from normal values were transferred to another map (deviation index isointegral map, DI map). We considered a reliable index of inferior myocardial infarction an area where the time-integral values were at least 2 SD lower than normal, in the inferior half of the thorax. A number of variables relative to instantaneous potential distribution and to isointegral maps were considered. The DI maps of the first 40 msec of QRS gave the most accurate criteria; in fact, an area of negative values 2 SD lower than normal was found in all group A patients and in 11 out of 15 group B patients (sensitivity 100% in group A, 73% in group B and specificity, 83%). Thus our results indicate that body surface potential maps have greater diagnostic information content than the 12 standard electrocardiographic leads and demonstrate the usefulness of the time integral analysis of body surface potentials for diagnostic interpretation.
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Papers by Tito Bertoni