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Biomedical subjects

C Moro

Publications and source records attributed to C Moro.

At least 19 recordsLinked to original sources
PubMed2000

[Recurrent ventricular fibrillation during a febrile illness in a patient with the Brugada syndrome].

Different situations have been involved in the origin of ventricular arrhythmic events in patients with the Brugada syndrome such as bradycardia, alcohol consumption and mental stress. We present a 30 year old male with recurrent ventricular fibrillation due to a febrile illness with intense sweating. He had been previously studied at our Unit in 1995 because of an episode of resuscitated cardiac arrest due to ventricular fibrillation. The twelve-lead electrocardiogram showed the typical characteristics of a patient with the Brugada syndrome. Different invasive and non-invasive tests performed were normal. He received a defibrillator and had no recurrences during 4 years of follow up. In March,1999, after an upper respiratory tract infection he had high fever treated with paracetamol but at down he had sweating and chills, followed by 3 defibrillator shocks. Late interrogation showed 5 episodes of ventricular fibrillation, two of them non-sustained, and the rest adequately treated by the defibrillator. Activation and inactivation kinetics for early INa are twofold faster at higher temperature, and shift activation and steady-state inactivation. This may explain the role of the temperature as a trigger for ventricular arrhythmias in our patient.

Adult↗
PubMed2000

A prospective multicenter study on the safety of a pacemaker with automatic energy control: influence of the electrical factor on chronic stimulation threshold. PEACE Investigators.

The effectiveness and safety of a pacemaker with automatic control of capture was evaluated in 162 patients followed at 27 Spanish centers. The aim of our prospective, multicenter, and randomized trial was to determine the relationship between the voltage output of the pulse generator and the stimulation threshold. We randomized 162 patients (107 men, mean age 75 +/- 12 years). We implanted a ventricular pacemaker model Regency SR+ or SC+ with Pacesetter's low polarization bipolar leads Membrane E 1450. The patients were randomized to receive Autocapture or not; group I (81 patients) Autocapture On, pulse output automatically adjusted and group II (81 patients) Autocapture Off, fixed output parameters (3.9 V, 0.37 ms). We performed a 6-month follow-up measuring stimulation threshold by means of the VARIO test and Autocapture test, evoked response signal, and R wave signal. The mean R wave was 15.77 +/- 3.5 mV at the end of the follow-up for group I, and 14.91 +/- 6.8 mV for group II (P = NS). The measured evoked response at the end of the follow-up was 9.25 mV in Group I and 8.48 mV in Group II (P = NS). The stimulation threshold was not different between groups. The current density created with the voltage and pulse width used in this study (< or = 3.9 V and 0.37 ms) at the tip of this electrode during the maturation process had no influence on the development of the chronic detection and stimulation thresholds.

Adult↗
PubMed2000

[Anatomopathological and biochemical correlation of lesions produced by standard and irrigated 4 mm radiofrequency catheters].

INTRODUCTION AND OBJECTIVES: The influence on the size of radiofrequency lesions by cooling of the tip of the electrode remains unclear. Moreover, the possible effects of two different cooling systems, closed and open, have not been well differentiated. We designed this study to compare both systems of irrigated-tip catheters and the lesions produced with standard 4 mm catheters and also to evaluate the pathological and biochemical marker release correlation (cardiac troponin I) in an experimental model. METHODS: The study was performed in 20 pigs. Applying between 1-8 radiofrequency pulses, at a power of 15, 25 or 50 watts, for 15-60 seconds to each animal. After 7 days, the pigs were sacrificed for anatomopathological study. RESULTS: A total of 54 lesions were produced, 25 with standard catheters and 29 with irrigated catheters. The mean volume of the lesions produced with standard catheters was 146 +/- 110 microl and with irrigated-tip catheters 856 +/- 864 microl (p < 0.001). Peak values of cardiac troponin I were also higher for irrigated catheters (18 +/- 15 ng/ml) than for standard (6.5 +/- 3 ng/ml). The correlation between the size of the lesion and the levels of cardiac troponin I were 0.86 and 0.79 with the standard and irrigated-tip catheters, respectively. The incidence of cratering was higher with standard catheters (60%) than with irrigated (27%). CONCLUSIONS: The lesions produced with an irrigated catheter are greater than those observed with standard catheters. The mean peak value of postablation cardiac troponin demonstrate a good correlation with the real size of the necrosis.

Animals↗
PubMed1998

Biochemical markers and cardiac troponin I release after radiofrequency catheter ablation: approach to size of necrosis.

BACKGROUND: We designed this study to determine the value of serum levels of several cardiac markers in patients who underwent radiofrequency ablation and to establish the utility of cardiac troponin I (cTnI). After radiofrequency ablation there is always a small localized endomyocardial necrosis. The volume of the necrosis may be estimated by the rise of several biochemical marker levels, classically creatinine kinase (CK) and CK-MB. cTnI is a newly available biochemical marker with a high cardiac specificity. METHODS AND RESULTS: We analyzed the data from 51 patients who underwent radiofrequency ablation and from 16 control patients who underwent an electrophysiologic study without ablation. The levels of CK, CK-MB mass, cTnI, and myoglobin were compared with clinical findings, ST-T wave abnormalities, and the presence of arrhythmias. The study shows that there is a higher release of cTnI compared with the standard markers CK, CK-MB, and myoglobin. A pathologic value of cTnI was found in 92% of the patients of the ablation group. CK-MB had a lower sensitivity (63%). The area under the receiver operating characteristic curve for cTnI was 0.9375, significantly superior to the other biochemical markers (P <.05). We found a moderate level of correlation between the number of radiofrequency pulses and cardiac cTnI release (r = 0.69, P <.0001). CONCLUSIONS: The serum level of cTnI detects the minor myocardial damage produced by radiofrequency ablation. This would be useful information to have in patients who might have the potential for other ischemic events. The other biochemical or ablation parameters usually reported, including the radiofrequency ablation parameters, have no good correlation with the size of the myocardial necrosis. Therefore we suggest that monitoring of cTnI is the best way to detect and quantify the size of myocardial necrosis created by radiofrequency ablation.

Adult↗
PubMed1998

[National Registry of Automatic Implantable Defibrillators in 1996].

The results of the Spanish Registry of Automatic Defibrillators implanted between February 1996 and January 1997 are reported. A questionnaire per patient was completed by every implanting physician, in every center. The questionnaire was designed by the Section of Electrophysiology and Arrhythmias of the Spanish Society of Cardiology. The data from 306 automatic defibrillators implanted were reported. The percentage of defibrillators per inhabitant in Spain is close to 1 per 100,000. Eighty-five percent were first implants, while a 13% were replacements. Most of the electrodes used were endocardial. Chronic ischemic heart disease was found in 54% of the patients. Forty-six percent of the patients had syncopal ventricular tachycardia, 31% ventricular fibrillation and 23% sustained monomorphic ventricular tachycardia. The generator pocket was pectoral in 87% of the patients and abdominal in 13%. The implant of the defibrillator was associated with other cardiac surgery in only 3% of the patients.

Aged↗
PubMed1998

[Electromagnetic interference between automatic defibrillators and digital and analog cellular telephones].

BACKGROUND AND OBJECTIVES: Functional pacemaker interference by mobile telephones has been described with analogical systems and with possible greater influence, digital systems, including inhibition and inadequate pacing. The influence of both system has not been extensively studied in patients with implantable cardioverter defibrillators (ICD). PATIENTS AND METHODS: We studied the influence of mobile phones, both digital and analogic network, on the performance of several models of defibrillators, in a standardised test set up designed to provide high sensitivity. The purpose of our study was to establish whether there are any influences on ICD functions, both in in vivo and in in vitro models. Several mobile phones, with different transmission powers, were moved towards the defibrillator and the electrode, under continuous documentation of defibrillator sensing and interrogation afterwards. The experimental model was performed with the aid of an arrhythmia simulator (Intersim) and demo-defibrillators. The tests were repeated both in and out of a solution of saline water with an impedance within normal human limits. RESULTS: Partial loss of telemetry was found in 14 patients, 8 with analogical phones and 6 with digital phones. Fourteen patients showed alterations only on the surface electrocardiogram channel and five on the intracavitary channel. The same results were reproduced in the in vitro model. However, the in vitro test allowed us to simulate multiple ventricular arrhythmias, and demonstrate the normal sensing and functioning of the defibrillator during a "spontaneous" arrhythmia. After testing, we demonstrate that no real oversensing/undersensing was documented in any device. There was no evidence of ICD reprogramming or pacing inhibition. In particular, no inadequate therapies were delivered. CONCLUSIONS: a) in our series, we have not demonstrated clinically significant electromagnetic interferences with mobile phones of digital or analogical networks: b) the in vitro model allowed us to conclude that even if a spontaneous arrhythmia appears, the function of the defibrillator is not altered; c) the use of mobile phones seems to be safe for defibrillator patients, and d) however, some basic rules, such as to maintain the phone at least 15 cm away from the defibrillator, are advised.

Defibrillators, Implantable↗
PubMed1998

Dosimetric and radiation protection considerations based on some cases of patient skin injuries in interventional cardiology.

Recently, several cases of skin injuries have been detected in patients undergoing cardiac radiofrequency catheter ablation. These procedures were performed on a biplane X-ray system used in a large Spanish hospital for interventional cardiology procedures. Interventional procedures performed and radiation lesions produced on patients are described. The radiation lesions were mainly erythematous lesions and chronic radiodermatitis. Results of the dosimetric evaluations and an analysis of the operational aspects of radiological protection are discussed. Poor image quality could have influenced the length of the procedures. Dose rate at the image intensifier entrance was within usual reported values in literature. However, the focus-to-skin distance for the horizontal X-ray beam was too short, resulting in a high skin dose rate. Additionally, X-ray beams are of fixed orientation, and accumulated skin dose in the patient's right side has been estimated as 11-15 Gy per procedure. In conclusion, practical radiation protection considerations to avoid further incidents of this sort are proposed, concerning the use of X-ray systems specially designed for interventional radiology, the improvement of cardiologists' training in radiation protection and routine patient dose measurements for complex interventional procedures.

Adolescent↗
PubMed1998

Cardiac troponin I and minor cardiac damage: biochemical markers in a clinical model of myocardial lesions.

Radiofrequency (RF) catheter ablation is the curative treatment of choice for many cardiac arrhythmias. After RF ablation there is always a small localized endomyocardial necrosis, necessary to abolish the arrhythmia. We designed this study to determine the serum concentrations of several cardiac markers in patients who underwent RF catheter ablation. The study shows a higher frequency of increase of serum cardiac troponin I (cTnI) than of creatine kinase (CK), the CK MB isoenzyme (CK-MB), or myoglobin. A pathological value of cTnI was found in 47 of 51 patients (92%) in the ablation group. The area under the ROC curve for cTnI was 0.9375, significantly higher than for the other biochemical markers (0.86, 0.76, and 0.75 for CK-MB, myoglobin, and CK, respectively), with P <0.05. We conclude that the serum concentration of cTnI is the best biochemical marker for detecting the minor myocardial damage produced by RF ablation.

Adult↗
PubMed1997

[Human and technical resources of arrhythmia units in Spain in 1995].

The results of the Spanish registry for electrophysiology and arrhythmias activity are presented. A questionnaire was sent to all of the Arrhythmia Units in Spain, directed to their human and technical resources, and activity. The questionnaire was designed by the Section of electrophysiology and Arrhythmias of the Spanish. Society of Cardiology. The existence of an arrhythmia Unit, as an autonomous center, was recognized in 26 cases, at the end of 1995. In 13 centers there was no Arrhythmia Unit, but 11 wanted to develop one and in 2 it was not considered. Seven centers expected to create an Arrhythmia Unit during 1996. The first Arrhythmia Unit in spain was created in 1979. We have considered as a basic requirement the functional existence of a specific cardiac electrophysiological laboratory. Only 34 hospitals already have a Laboratory and 5 are waiting for the development of one. In 21 hospitals there are cardiologists particularly dedicated to electrophysiology, the number varies between 1 and 3 in each hospital. Radiofrequency catheter ablation is now considered the technique of choice for the treatment of most cardiac arrhythmias. This technique is currently being performed in Spain in 29 Hospitals and an additional 4 are expected to be able to perform it in the near future. Twenty-five hospitals implant automatic defibrillators, and the mean defibrillators implanted per hospital and year is 9.8 +/- 10.1.

Arrhythmias, Cardiac↗
PubMed1997

[Evaluation of biochemical markers of myocardial lesion after radiofrequency ablation. Value of troponin I].

INTRODUCTION AND OBJECTIVES: Radiofrequency catheter ablation is the curative treatment of choice for many cardiac arrhythmias. After radiofrequency ablation there is always a localized endomyocardial necrosis, which is necessary to eliminate the arrhythmia. The volume of the necrosis may be evaluated by the rise of several biochemical markers, classically CK and CK-MB. However, the sensitivity and specificity of these markers are not optimal and are probably less than ideal for this purpose. Cardiac Troponin I (cTnI) is a newly available biochemical marker available, with a high cardiac specificity. We designed this study in order to determine the value of serum levels of several cardiac markers in patients who underwent radiofrequency catheter ablation and to establish the utility of cTnI. METHODS: We analyzed the data from 51 patients who underwent radiofrequency ablation and from 16 control patients. In respect to the ablation target, we included in the study 14 left accessory pathways, 7 right accessory pathways, 12 atrioventricular nodal reentry tachycardia, 5 ventricular tachycardia and 13 atrial flutter or fibrillation. The levels of CK, CK-MB, cTnI, and myoglobin were compared with clinical findings, ST-T wave abnormalities and the presence of arrhythmias after ablation. To evaluate the diagnostic capability for each biochemical marker we used the ROC curves. RESULTS: A pathological value of cTnI was found in 47 out of 51 (92%) patients in the ablation group. CK-MB had a lower sensitivity (63%). The sensitivity for the other biochemical markers ranged from 30% for CK to 67% for Myoglobin. The area under the ROC curve for cTnI was 0.9375, significantly superior to the other biochemical markers (0.86, 0.76, 0.75 for MB, Myoglobin, CK respectively) (p < 0.05). The lowest cTnI released was found in patients after nodal reentry tachycardia ablation and the highest after atrial flutter ablation. cTnI increased above normal values in 4 patients in the control group (patients who underwent an electrophysiological study without catheter ablation). We found a moderate level of correlation between the number of radiofrequency pulses and cardiac cTnI release (r = 0.69; p < 0.0001). The correlation was different in each target, ranging between r = 0.25 (p = NS, 0.43) for atrial flutter and fibrillation to r = 0.99 (p < 0.0001) for ventricular tachycardia. CONCLUSIONS: cTnI had the greatest sensitivity (92%) for detecting minor myocardial damage. Thus, we can conclude that the serum level of cTnI detects the minor myocardial damage produced by radiofrequency ablation.

Adult↗
PubMed1996

Signal averaged electrocardiography in patients with acute myocarditis.

This report describes the late potentials obtained by signal averaged electrocardiography (ECG) in 19 patients (13 male, 6 female, mean age 31 +/- 17 years) with acute myocarditis and their evolution. Five patients (26%) had positive signal averaged ECG in time domain analysis and two had technically inadequate signal averaged ECG. All five patients with positive signal averaged ECG, and 6 of the 12 patients with negative, developed heart failure (100%). One patient died. Signal averaged ECG was repeated at 3 months in all 18 surviving patients. Two patients had a good clinical evolution, normalized left ventricular function, and changed from positive to negative signal averaged ECG. All patients with heart failure on admission with negative signal averaged ECG had clinical improvement. Late potentials in patients with acute myocarditis are associated with a worse prognosis and greater extent of myocardial damage.

Action Potentials↗
PubMed1995

Heart rate variability and inappropriate sinus tachycardia after catheter ablation of supraventricular tachycardia.

Sinus tachycardia has been reported after radiofrequency catheter ablation of supraventricular tachycardia. Frequently, these patients require beta-blocking agents for symptomatic control. The purpose of this study was to evaluate prospectively the incidence of inappropriate sinus tachycardia and heart rate variability after ablation of atrioventricular nodal reentrant tachycardia and accessory pathways. Patients undergoing ablation had 24-h ambulatory monitoring ECG (Holter) performed before the procedure, on the day of the ablation, and 3 months afterwards. There were 170 patients, mean age 48 +/- 23 years; 93 were female. A complete study of the 24-h Holter with analysis of heart rate variability: SD, rMSSD, pNN50, high and low frequency was obtained. There was a low prevalence of inappropriate sinus tachycardia after the ablation procedure (10 of 170 patients: five with four atrioventricular nodal reentry, with posteroseptal accessory pathways and one of the latter following ablation of the left accessory pathway). There was no modification of time and frequency domain parameters of heart rate variability in the remaining patients who underwent radiofrequency ablation. Holter monitoring 3 months after ablation showed that parameters of heart rate and heart rate variability had normalized in patients who had developed inappropriate sinus tachycardia. Inappropriate sinus tachycardia may be initiated by both radiofrequency ablation of atrioventricular nodal reentrant tachycardia and radiofrequency ablation of posteroseptal accessory pathways. Specific damage to the posteroseptal region is responsible for these changes, which usually recover spontaneously after 3 months.

Adult↗
PubMed1995

Part-set cuing in incidental and implicit memory.

We report inhibitory effects of part-set cuing in an incidental memory task. Even when subjects did not expect a memory test during study, re-presentation of some of the study words (Experiments 1 and 2) or presentation of related words (Experiment 3) during test inhibited memory performance. Also, in Experiment 3, inhibitory effects of part-set cuing emerged when subjects were completing fragments of the studied words, but only when they were explicitly trying to remember those words from the list. There was a facilitatory effect of part-set cuing when subjects were simply completing the fragments with the first words they could think of. These results suggest that the part-set cuing effect is largely independent of what happens during the study phase and dependent on a deliberate effort to remember during the test phase.

Attention↗
PubMed1994

Cardiovascular toxicities related to the infusion of cryopreserved grafts: results of a controlled study.

To evaluate cardiovascular toxicities associated with the infusion of cryopreserved grafts, we prospectively monitored the infusions of 29 autologous bone marrow transplant (BMT) recipients. Fifteen allogeneic BMT recipients served as a control group. Cardiac rhythm was recorded continuously with the Holter technique from at least 2 h before the start of graft infusion until 24 h after completion. Blood pressure was closely monitored during the same period. Graft infusions were performed through a standard transfusion filter with breaks between aliquots. When the infusion had commenced, diuretics were given frequently (40 and 40% of allogeneic BMT and autologous BMT recipients, respectively) to avoid fluid overload. Non-cardiovascular clinical toxicities were observed more frequently in autologous BMT patients (41% vs 6%, p = 0.02) and no significant differences were seen between autograft and allograft recipients in any of the measured cardiovascular parameters. The heart rate decreased slightly in both groups but no patient in either group had a heart rate of < 60 b.p.m. or heart block. No significant changes in blood pressure were detected in either group. Ventricular ectopic beats/atrial ectopic beats ratio increased in the autologous BMT group after graft infusion (0.7 vs 0, p = 0.1). Time to engraftment did not differ significantly from other published series. Our results suggest that increasing infusion time of cryopreserved material and using a standard filter may reduce toxicities associated with the infusion of cryopreserved grafts. Early administration of diuretics may contribute to better control of blood pressure.

Adolescent↗
PubMed1994

[Usefulness of the RR variability in the diagnosis of neurogenic syncope].

UNLABELLED: INTRODUCTION AND PURPOSES: Autonomic nervous system plays an important role in the pathogenesis of vasovagal/vasodepressor syncope and may also be assessed by the RR variability analysis. Head up tilt test (HUT) is a currently established tool to evaluate patients with neuromediated syncope. However, the relationship between heart rate variability and tilt induced syncope is not established. The purpose of this study was to assess the differences in heart rate variability among patients with syncope and negative or positive tilt test. METHODS: Fifty patients (mean age 33 +/- 17 years, 24 female, 26 male) with syncope underwent tilt test (20 min, 80 degrees tilt and 20 min more under isoproterenol infusion). Twenty-three patients have a negative tilt, the rest had a positive test. There were not significant differences in age or sex. Immediately after the HUT a 24-hour ambulatory electrocardiogram was performed (Marquette system 8000, 002A program). The parameters measured during Holter monitoring were: SDANN, SD, rMSSD, pNN50 and frequency analysis of heart rate spectrum (low frequency 0.04-0.15 Hz, high frequency 0.15-0.4 Hz and the relation low/high). No significant differences were detected in age and sex in patients with and without positive HUT. RESULTS: pNN50 and rMSSD were the best predictors of the results of tilt (p = 0.006). SDANN and SDNN were not useful parameter. The finding of a value of pNN50 > 25% (value significantly different between patients with HUT--and +) have a specificity for predicting a positive HUT of 82.6%, with a sensibility of 51.8%. Positive predictive value was 77%. As can be easily understood, if the cut value of pNN50 is lowered, its sensibility increased and the specificity. decreased. In the frequency analysis only the relation low/high (L/H) was significantly different between both populations. CONCLUSIONS: Heart rate variability is a useful tool in the evaluation of patients with vasovagal syncope, that may identify patients with chronically elevated vagal tone and thus may predict tilt test results.

Adult↗