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Biomedical subjects

M Santomauro

Publications and source records attributed to M Santomauro.

At least 19 recordsLinked to original sources
PubMed1996

Subacute cardiac rupture complicating myocardial infarction. A case report.

The authors have focused this study on the emergence of subacute ventricular free wall rupture in a seventy-six-year-old patient admitted to hospital for inferior acute myocardial infarction. After six days he showed clinical signs of bradycardia and hypotension evolving to electromechanical dissociation. Given an adequate pharmacologic therapy, the patient was submitted to echocardiography, which was believed to be consistent with myocardial rupture, showing a moderate to large pericardial effusion. Pericardiocentesis of 150 mL of bloody fluid resulted in a further improvement in his hemodynamics. The patient underwent cardiac surgery with repair of the myocardial rupture through a large diaphragmatic infarction by a Dacron polyester fiber graft and pacemaker placement. In conclusion the authors confirm the relevant role of clinical data such as persistent chest pain and hemodynamic instability and the value of echocardiography in identifying subacute myocardial free wall rupture after an episode of acute myocardial infarction.

Aged↗
PubMed1996

[Radiofrequency catheter ablation of atrial tachycardia: technique, results and follow-up].

BACKGROUND: Recently radiofrequency (RF) catheter ablation (CA) of atrial tachycardia (AT) showed to be highly effective with a low incidence of compliance. Aim of our study was to report the results and follow-up of RFCA of drug-refractory AT in 59 consecutive patients (pts). METHODS: Two mapping techniques were used to localize the ablation site of AT: the earliest atrial activation and the pace-mapping. Traumatic interruption of AT was used to verify the ablation site identified by the previous procedures. Moreover we evaluated the sensitivity, specificity and the positive predictive value of the three mapping techniques. RESULTS: AT was successfully treated in 55/59 (93.2%) pts with a mean of 4.0 +/- 3.8 (range 1-16) RF pulses for patient. The mean procedure time was 185.2 +/- 48.5 min with a mean rx-time of 41.5 +/- 21.3 min. An interval between the onset of the intracavitary atrial deflection and the onset of the P-wave, during atrial tachycardia, (AP interval) > or = 30 ms and pace-mapping concordant sequence were highly sensitive (90.9% and 89.1%) but less specific (49.2% and 33.9%) in identifying the site of ablation. By using atrial tachycardia traumatic interruption combined with the AP interval > 30 ms or the pace-mapping concordant sequence we obtained a specificity of 78.7% and 77.0% respectively and a positive predictive value of 48.0% and 46.8% respectively. Four recurrences (7.3%) were observed during a mean follow-up of 23.4 +/- 13.3 months. In the 22 (37.3%) pts with dilated cardiomyopathy, chest Xr and echocardiography showed a significant decrease of cardiothoracic index (0.56 +/- 0.08 pre ablation, 0.43 +/- 0.07 post ablation, p < 0.001) and end-diastolic diameter (64 +/- 8 mm pre ablation, 52 +/- 8 mm post ablation, p < 0.001) and a significant improvement of left ventricular ejection fraction (37 +/- 9% pre ablation, 48 +/- 11% post ablation, p < 0.05). CONCLUSION: The RFCA of AT was effective and safe. Moreover we observed a hemodynamic improvement in patients with reduced ejection fraction and increased cardiac volumes. An AP interval > or = 30 ms and the pace-mapping concordant sequence were reliable features to predict the outcome of the ablation procedure. Traumatic ablation of atrial tachycardia improved the specificity and the positive predictive value of these two mapping techniques and was able to predict the response to radiofrequency with a high specificity.

Catheter Ablation↗
PubMed1996

[Computerized follow-up cards for ambulatory patients with implanted pacemaker or defibrillator].

The follow up of pacemaker and defibrillator dependent patients has a significant role for both the evaluation of pacing effectiveness and check of hemodynamic advantages about patient's quality of life. The bulky paper archives are often inaccurate, hampering the consultation. At present the paper card is the only document which can be utilized to record some data concerning the implant and patient clinical story. Therefore, there is the necessity for a card that can include all patient's data, and the implant and programming pacemaker/defibrillator data during follow up. This new pacemaker card has portable file or data-base including shared data with safety mechanism, which can be utilized in several controls by different users (physicians, hospital ward, primary care units, insurance companies). The pacemaker card includes a chip that permits to store a considerable amount of data; it can be update in every further medical control, in observance of laws. The card Chip Operating System (C.O.S.) consists of a microchip with a memory completely managed by the operating system inside the chip itself. The card can be read by means of a GCR-200 modem linked with a PC IBM-compatible computer and the data can be updated during the follow up. The pacemaker-defibrillator card will appear immediately on screen, and it can be printed, updated and/or modified by a Microsoft Windows operating programme. With this pacemaker card we are able to ensure serviceable medical work, particularly in terms of cost/benefit ratio giving to patient more and more reasoning and safe service.

Database Management Systems↗
PubMed1994

[Atrioventricular conduction before and after the radiofrequency catheter ablation of a nodal reentry tachycardia circuit].

Aim of our study was to retrospectively evaluate atrioventricular conduction 24 hours after selective radiofrequency catheter ablation of the fast pathway or after selective ablation of the slow pathway of the atrioventricular nodal reentrant tachycardia circuit. Electrophysiologic modifications were retrospectively analyzed in 47/48 patients successfully submitted to fast pathway ablation and in 90/93 patients successfully submitted to slow pathway ablation. The atrioventricular conduction intervals (P-Q and A-H), both anterograde and retrograde Wenckebach point, the effective refractory period of atrioventricular node and the atrioventricular node function curve were evaluated before and after selective radiofrequency catheter ablation of slow and fast pathway. We identified the fast pathway ablation potential as: A:V ratio > or = 2:1, His electrogram < or = 150 microV. The slow pathway potential was identified as the widest, sharpest and latest atrial electrogram recorded during sinus rhythm in the posteroseptal region of the atrioventricular junction or as the widest, sharpest and earliest observed during retrograde conduction. We observed a significant increase in the P-Q and A-H intervals in patients submitted to fast pathway ablation, while no significant modification of these parameters was appreciated in patients submitted to slow pathway ablation. No significant modification of anterograde Wenckebach point (NS) was observed in patients submitted to successfully ablation of fast pathway while a statistically significant increase in anterograde Wenckebach point (p = 0.03) was observed in patients submitted to slow pathway ablation. After selective fast pathway ablation, retrograde conduction was absent in 82.9% of patients submitted to ablation; in the remaining 17.1% a significant increase of retrograde Wenckebach point was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Platelet aggregability in patients with a VVI pacemaker.

Several studies have suggested an increased incidence of thromboembolic events in patients with VVI pacemaker (VVI patients); furthermore, other authors have demonstrated that a treatment with anticoagulants or antiplatelet drugs may be effective in reducing thromboembolic events, thus suggesting an increased formation of platelet thrombi in these patients. In this respect, platelet aggregability was investigated in ten VVI patients and ten age- and sex-matched subjects. beta-thromboglobulin (beta-Tg) and platelet factor 4 (PF4) plasma levels were determined as well as platelet aggregation induced by ADP, collagen, epinephrine, and arachidonic acid. Plasma beta-Tg levels were increased in the patient group (86 +/- 24 vs 24 +/- 13 ng/mL; P < 0.001) in presence of normal PF4 values (14 +/- 11 vs 13 +/- 6 ng/mL; NS). Aggregation curves showed abnormal values of maximal amplitude, slope, and lag time. In particular, maximal amplitude was significantly higher in VVI patients as compared with controls (ADP P < 0.01, collagen P < 0.001, adrenaline P < 0.01, arachidonic acid P < 0.05). These findings strongly suggest an increase of platelet activity in VVI patients.

Adenosine Diphosphate↗
PubMed1993

[Ablation of paroxysmal tachycardia in Wolff-Parkinson-White syndrome].

Surgical or catheter ablation of accessory pathways by means of high energy shock has been substantial associated with morbidity and mortality. On the contrary radiofrequency current, an alternative energy source for ablation, has a low incidence of complications and a very high success rate. Aim of this study was to relate about the results using catheter ablation of accessory pathways by radiofrequency current in our Electrophysiologic laboratory. Radiofrequency current (20-40 W) was delivered between a large-tip catheter electrode positioned against the mitral or tricuspid anulus and a standard adhesive electrosurgical dispersive pad applied to the left chest wall. When possible radiofrequency delivery was guided by catheter recordings of accessory pathway activation. Ablation was attempted in 181 patients with 191 accessory pathways. We obtained successful ablation of 187/191 accessory pathways and accessory pathway conduction was eliminated in 177/181 patients. During a mean follow-up of 14 +/- 10 months preexcitation returned in 7 patients (3.9%). All underwent a second successful ablation. In 1 patient, during the procedure, we observed a transient ischemic attack, with no complications. In accordance to other reports we conclude that radiofrequency ablation is highly effective in ablating accessory pathways, with low morbidity and no mortality.

Adolescent↗
PubMed1993

[A methodological approach to the transcatheter radiofrequency ablation of anomalous Kent-type pathways].

Aim of this study is to suggest our methodological approach for transcatheter ablation of Kent bundles by radiofrequency energy as to the potential ablation sites, the need in unipolar or bipolar recording mode, single catheter or multiple catheters mapping of anomalous pathways, the vascular approach for both left sited and right sited anomalous pathways, and finally the duration and power to supply. The recording of Kent potential and/or a Va-QRS interval > or = 0 ms have been considered significant predictors of success (respectively p < 0.001 and p < 0.05). The unipolar recording mode has been considered critical in the choice of ablation site in 47 (29.9%) patients. A 6-catheter approach for both diagnostic electrophysiologic studies and mapping allowed us to easily localize accessory pathways and to record either a probable or possible Kent potential in a high percentage of patients and to reduce the permanence of the ablation catheter in the left ventricle. By transaortic retrograde approach in ablating left sited anomalous pathways, we obtained a high success rate, while right sited accessory pathway were approached from the inferior vena cava. In right sited anomalous pathway we delivered radiofrequency energy for a longer time in order to avoid a relapse soon after the procedure. We performed ablation of 174/178 (97.7%) anomalous pathways in 165/169 (97.6%) patients. We observed a 3.8% relapse during a mean follow up of 13 +/- 9 months.

Adolescent↗
PubMed1993

[Cardiac effects of GH].

To investigate cardiac effects of excess and deficiency of growth hormone (GH) we studied twenty acromegalic subjects and eleven adult patients with GH deficiency by means of a non invasive method, the Doppler echocardiography. The results obtained in the group of patients were compared with those of two groups of twenty and eleven normal subjects, respectively, age and sex matched. The age of the acromegalic patients ranged from 20 to 62 years. Nineteen patients were considered to have active acromegaly at the time of the study. Mean duration of disease since treatment was 12 +/- 5 years (range 5 to 24 years). The age of GH deficient adults ranged from 21 to 33 years. All these patients have been treated with extractive GH over nine years and the therapy withdrawal was performed at least three years before entering the study. In the group of acromegalic patients, a subgroup including nine patients with mild to moderate hypertension was considered. All subjects gave informed consent and the study protocol was approved by the Ethical Committee of the Medical School of Naples. Right ventricular free wall thickness resulted significantly increased in acromegalic patients (8 +/- 2 vs 4 +/- 1 mm; p < 0.001). Left ventricular mass index was augmented both in the whole group and in the subgroups of normotensive and hypertensive acromegalics as compared with normals (134 +/- 33 p < 0.001, 115 +/- 20 p < 0.01 and 156 +/- 31 p < 0.001 vs 80 +/- 18 g.m-2). Ejection phase indices were normal in patient group, while impaired left and right ventricular diastolic filling was found.(ABSTRACT TRUNCATED AT 250 WORDS)

Acromegaly↗
PubMed1993

Clinical experience with the transvenous Medtronic Pacer Cardioverter Defibrillator (PCD) System.

We review our experience with the transvenous Medtronic Pacer Cardioverter Defibrillator System (Model 7217B), a multifunction implantable pacer defibrillator combined with a transvenous lead system (Transvene). From April 1991 to October 1992, we implanted this device in 19 consecutive patients (11 men and 8 women; average age, 56.5 years). Nine patients (47.4%), 5 with coronary artery disease and 4 with dilated cardiomyopathy, had an ejection fraction of < 30%. The average operative time was 129 minutes. In 18 patients (94.7%), the transvenous lead system provided effective sensing, pacing, and defibrillation during intraoperative testing. In each of these cases, the defibrillation threshold was less than 18 J. In 1 patient (5.3%), it was necessary to switch to epicardial leads, which were implanted through a left thoracotomy. All patients were extubated in the recovery room. The average hospital stay was 8 days. There was no early mortality or morbidity. During a maximum follow-up period of 17 months (mean, 9.2 months), no sudden death occurred. The implantable system terminated 245 ventricular tachycardia episodes in 14 patients (73.7%) and 82 ventricular fibrillation episodes in 13 patients (68.4%). Two hundred eleven (86.1%) of the ventricular tachycardia episodes were resolved by antitachycardia pacing alone. In 2 patients (10.5%), the caval electrode became dislocated; repositioning of the electrode was followed by repeat defibrillation threshold evaluation. Our experience shows that the transvenous Medtronic Pacer Cardioverter Defibrillator System provides safe, effective treatment of ventricular tachyarrhythmias. Because the perioperative mortality and morbidity are extremely low, use of this device may be particularly beneficial in patients with a high operative risk. Moreover, the lower number of unpleasant therapeutic shocks should increase patient a acceptance of the device.

Adult↗
PubMed1992

Influence of atenolol on the relationship between heart rate and QT interval in patients with exercise-induced myocardial ischemia.

The aim of this study was to analyze the relationship between heart rate and QT interval (HR-QT) during exercise in control subjects (Group A) and in patients with coronary artery disease (CAD) with effort angina and without previous myocardial infarction (MI) (Group B). The diagnosis of CAD was confirmed by coronarographic examination. The correlation HR-QT was significant (p < 0.001) in both groups on effort and at recovery. The analysis of the regression HR-QT was carried out separately, both on effort in upright position and at rest in supine position, to avoid the influence of posture on QT length. During effort, the regression line showed lower slope and intercept values in Group B (p < 0.001) than those for Group A. A similar behavior was also observed at rest. Thus, at the highest heart rate, where ECG signs of ischemia (ST depression > 1 mm) frequently occurred, a longer QT interval was present in Group B. Moreover, in Group B, the QT interval in the presence of ECG signs of ischemia was significantly longer (p < 0.01) than in Group A at comparable heart rates both on effort and at rest, thereby confirming the result obtained by comparing both regression lines. The same effort protocol was repeated in Group B patients after acute administration of atenolol 100 mg per os. After atenolol administration, the analysis of the regression HR-QT in Group B clearly showed a shorter QT interval than that obtained in washout period during the baseline test at the highest heart rates where the ECG frequently showed signs of ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1992

Comparison between exercise and trans-oesophageal atrial pacing in patients with coronary artery disease: technetium-99m methoxy isobutyl isonitrile simultaneous evaluation of ventricular function and myocardial perfusion.

In this study we compared the results of exercise and trans-oesophageal atrial pacing (TAP) technetium-99m methoxyisobutyl isonitrile (99mTc-SESTAMIBI) cardiac imaging in the evaluation of left ventricular (LV) function and myocardial perfusion in patients with angiographically proven coronary artery disease. Ten patients (8 men and 2 women, mean age 59 +/- 6 years) were submitted to 3 separate injections of 99mTc-SESTAMIBI, one under control conditions, one after exercise and one after TAP. LV ejection fraction, as measured by electrocardiogram (ECG) gated first pass, decreased from 49 +/- 5% under control conditions to 42 +/- 6% during exercise (P less than 0.05 versus control) and to 43 +/- 8% during TAP (P less than 0.05 versus control and insignificant change versus exercise). Segmental myocardial perfusion analysis was performed on a total of 150 myocardial segments. On both exercise and TAP 99mTc-SESTAMIBI studies, 103 segments (69% of the total) were normal, 32 (21%) had reversible, and 15 (10%) irreversible, perfusion defects. Relative regional tracer uptake was not statistically different between exercise and TAP in normal regions (91.1 +/- 9.1% versus 90.7 +/- 8.5%, respectively), in regions with reversible (61.9 +/- 12% versus 62.4 +/- 10.4%, respectively) and irreversible perfusion defects (55.8 +/- 7.8% versus 58.8 +/- 9.5%, respectively). Our results demonstrated that 99mTc-SESTAMIBI TAP cardiac imaging shows similar results to 99mTc-SESTAMIBI exercise myocardial scintigraphy in the assessment of LV function and myocardial perfusion in patients with coronary artery disease.

Cardiac Pacing, Artificial↗
PubMed1992

Follow-up of a respiratory rate modulated pacemaker.

The efficacy of 27 respiration sensitive rate modulated pacemakers (Biorate RDP-3 Biotec) implanted in the left pectoral area was evaluated every 3 months during a mean follow-up period of 29 months (range 10-50 months). Rate modulation function was unchanged other than for three patients in whom the auxiliary leads became displaced. Two implants lost ventricular sensing in this nonprogrammable model. In all but the three patients, Holter monitoring demonstrated pacing rate variation corresponding to daily activity. Stress test duration increased from 8.2 +/- 1.5 minutes (in fixed rate VVI rate) to 12.83 +/- 2.0 minutes (in the VVIR mode) (P less than 0.05). Right arm movement increased the pacing rate by 5 +/- 3 beats/min (NS), while the left arm movement increase was 30 +/- 5 beats/min (P less than 0.05). Mental, arithmetic, and nifedipine tests did not change the rate modulated pacing rate. The system responded to a change in respiratory rate by an increase in stimulation rate. A satisfactory response in sensitivity and velocity was present only with medium-high workloads. Interference with rate modulation occurred with movement of the arm ipsilateral to the implanted pulse generator.

Atrial Fibrillation↗
PubMed1992

Evaluation, by noninvasive methods, of the effects of acute loss of thyroid hormones on the heart.

To evaluate the effects of the acute loss of thyroid hormones on the heart the authors studied 11 women with acute hypothyroidism. The cardiac study was performed by means of electrocardiography (ECG), radionuclide ventriculography (RNV) at rest and under effort, and monodimensional echocardiography (MD-echo) and was repeated with ECG and MD-echo after six months of thyroxine suppressive therapy. The ECG showed a significant prolongation of QT interval and flattening and inversion of T wave with normal heart rate. The MD-echo revealed left ventricular function in the normal range and normal left ventricular dimensions. RNV showed the ejection fraction in the lower normal range at rest, which increased to a smaller extent under effort in comparison with a control group. The ECG performed during suppressive therapy with L-thyroxine yielded normal findings with an increase of heart rate and of R wave amplitude, and the MD-echo showed no significant variations of cardiac function due to the increase of heart rate.

Adult↗
PubMed1992

Diagnosis of coronary artery disease with Tc 99m-methoxy isobutyl isonitrile and transesophageal pacing.

Recently the use of a new radioactive agent with physical and biological properties more favorable than those of thallium 201, methoxy-isobutyl-isonitrile (MIBI) labeled with technetium 99m (Tc 99m), has permitted simultaneous performance of perfusion and function studies in ischemic cardiopathy. Transesophageal atrial pacing (TAP) technique has evolved as an alternative provocative test of ischemia. The authors compared the capability of Tc 99m-MIBI myocardial scintigraphy, combined with TAP, with that of Tc 99m-MIBI, combined with maximal stress test, in the diagnosis of ischemic cardiopathy. They studied 11 patients with a clinical history of angina pectoris. Myocardial scintigraphy was performed at rest, after stress test, and after TAP. Finally, all the patients underwent coronary angiography. The analysis of myocardial perfusion images on both Tc 99m-MIBI associated with TAP and with stress demonstrated, in 165 myocardial segments examined: 143 normal, 20 reversible defects, 2 irreversible defects. The concordance of localization between coronarographic data and scintigraphic reversible and irreversible defects was 85%. In conclusion TAP proves to be a valid and sensitive provocative test of ischemia when combined with myocardial scintigraphy and with Tc 99m-MIBI.

Cardiac Pacing, Artificial↗
PubMed1991

Fourier analysis in patients with different pacing modes.

The purpose of this study was to evaluate the usefulness of phase analysis in detecting the altered activation sequence induced by different pacing modes. Radionuclide ventriculography and planar gated blood pool scintigraphy were performed at rest in 56 patients with different pacemakers. This method permitted us to localize the pacemaker impulse site in the right ventricle and its diffusion in the heart. In patients with VVI pacemaker, this technique showed an evident asynchronism of contraction and relaxation of each ventricle and the standard deviation of phase angle (sigma), calculated by computer, is greater during pacing than sinus rhythm for left (LV) and right (RV) ventricles (LV sigma: 17 degrees +/- 4 vs 11 degrees +/- 3, less than 0.001; RV sigma: 31 degrees +/- 7 vs 14 degrees +/- 4, P less than 0.001). In the patients with VVI rate responsive pacemakers, the LV sigma changed from 18.5 +/- 3 under pacing to 11 degrees +/- 3 in sinus rhythm, P less than 0.001, while the RV sigma changed from 30 degrees +/- 8 to 14 degrees +/- 4, P less than 0.001. Instead in the patients with DDD pacemakers, the LV sigma changed from 15.5 degrees +/- 2 under pacing to 11 degrees +/- 3 in sinus rhythm, P less than 0.05, while the RV sigma changed from 29.1 degrees +/- 6 to 14 degrees +/- 4, P less than 0.001.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Pacing, Artificial↗
PubMed1991

Efficacy of ticlopidine in the prevention of thromboembolic events in patients with VVI pacemakers.

This study was designed to evaluate whether long-term treatment with ticlopidine reduces the incidence of thromboembolic episodes in patients with a VVI pacemaker. One hundred eleven patients with a VVI pacemaker were randomly assigned to two groups: group A (52 patients) was treated with ticlopidine at the dose of 250 mg a day; and group B (59 patients) was not treated and served as a control group. The primary analysis of efficacy of ticlopidine was based on the occurrence of thromboembolic episodes and of cardiovascular and cerebrovascular deaths. The mean follow-up period was 66 months. In group A, there was a significant reduction in the incidence of thromboembolic episodes (P less than 0.05) with a smaller incidence of total cardiovascular and cerebrovascular deaths (8 in group A and 18 in group B; P = 0.05) as compared with group B. Twelve percent of patients had moderate side effects with 1 dropout (epistaxis). Our data confirm the high incidence of thromboembolic events in patients with a VVI pacemaker and demonstrate the efficacy of ticlopidine in preventing them.

Aged↗
PubMed1991

[Anaerobic threshold in the evaluation of heart function in patients with rate-responsive pacemaker].

It is very difficult to evaluate the ability of carrying out physical exercise in patients with rate responsive (RR) pacemaker (PM). However, the anaerobic threshold (AT) proved to be a useful parameter in the evaluation of cardiac function. The AT can be easily reproduced and not influenced from emotional aspects of both the patient and the physician, moreover being under maximum and then easy to achieve. Aims of our study were: to evaluate if the cardiopulmonary stress test can represent a method to be used for a more correct rate responsive pacemaker programming; to compare the data obtained of 3 rate responsive pacemakers steered by different sensors. We have studied 24 patients, of whom 10 with Activitrax (A), 8 with Meta (M), and 6 with Phymos MPT (P) pacemakers. Patients were submitted to symptoms limited cycloergometer stress test at 2 different settings: fixed rate at 70 b/min; increasing rate at until 85% of maximum heart rate for each patient, with range 0 + 10 W/min. Gas exchange data were continuously collected using an automated system (Medical Graphic System 2001) based on Whipp and Wasserman's method.(ABSTRACT TRUNCATED AT 250 WORDS)

Anaerobic Threshold↗