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Biomedical subjects

C Menozzi

Publications and source records attributed to C Menozzi.

At least 55 records · Page 3Linked to original sources
PubMed1990

[Syncope caused by paroxysmal atrial fibrillation and flutter: diagnostic usefulness of electrophysiological studies in the erect and supine positions].

In this study, we verified if the induction of atrial fibrillation/flutter, during the electrophysiological study, could be useful for the evaluation of syncope of unknown origin. Of 292 patients who underwent an electrophysiological study for unexplained symptoms, we selected 15 patients (5.1%) affected by syncope and pre-syncope. In these, the induction of atrial fibrillation (14 patients) or flutter (1 patient) just at the onset caused, the reproduction of the spontaneous symptoms. No other cause could be identified. These patients were affected by: 1) syncope or pre-syncope without electrocardiographic documentation of paroxysmal atrial fibrillation/flutter 2) syncope or presyncope and documented asymptomatic episodes of paroxysmal atrial fibrillation/flutter. Palpitations closely preceded or followed the syncope in 11/15 patients. Symptom reproduction was obtained in the supine position in 3 patients (heart rate 180 +/- 82 beat/min, systolic blood pressure 53 +/- 6 mmHg) and in the upright position in 12 patients (heart rate 177 +/- 24, systolic blood pressure 65 +/- 18 mmHg). The arrhythmia was induced by incremental atrial pacing or premature atrial beats in 3 cases, ramp in 3 cases and burst--mean rate 339 +/- 48 beat/min--in 9 cases. The arrhythmia lasted for a period of time ranging from a minimum of 1 mm to a maximum of 24 hours (median 1 hour). During sinus rhythm, an abnormal vasodepressor reflex (with a systolic blood pressure fall greater than or equal to 50 mmHg) could be induced in 7/9 patients by carotid sinus massage or 60 degrees tilt test.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial Fibrillation↗
PubMed1990

[Carotid sinus syndrome and sick sinus syndrome: 2 frequent and distinct indications for pacemaker implantation].

UNLABELLED: At present, patients affected by carotid sinus syndrome and, more general by speaking, by vasovagal syncopes, are being considered more and more for pacemaker implant. However, neither the real incidence of the carotid sinus syndrome or its relation with the sick sinus syndrome with which it is often associated or even confused is precisely known. Of a total of 298 consecutive pacemaker implants, 36 (12%) were executed for carotid sinus syndrome, 33 (11%) for sick sinus syndrome and 24 (8%) for both. The annual incidence was respectively of 40, 37 and 26 implants per year/million of inhabitants. Patients affected by carotid sinus syndrome, when compared with those affected by sick sinus syndrome, showed: a higher prevalence of syncopes (97 vs 42%) more syncopal episodes per patient (2.9 +/- 2 vs 1.8 +/- 0.9), a lower prevalence of associated cardiac diseases (53 vs 100%), cardiac enlargement (36 vs 88%), heart failure (6 vs 36%) and paroxysmal atrial fibrillation (0 vs 97%), a more frequent indication to VVI pacing (75 vs 3%). Generally, when both syndromes were present, the patients showed intermediate characteristics. IN CONCLUSION: carotid sinus syndrome is a frequent indication of cardiac pacing as sick sinus syndrome; even if an association is present in about one third of patients, a distinction between carotid sinus syndrome and sick sinus syndrome is justified by theoretical and practical considerations.

Aged↗
PubMed1989

Ventricular and dual chamber pacing for treatment of carotid sinus syndrome.

Thirty-nine consecutive patients with recurrent syncope and either cardioinhibitory or mixed type carotid sinus syndrome were studied to determine the efficacy of ventricular (VVI) pacing in 16, and dual chamber (DDD/DVI) in 23 patients. Only those patients affected by the isolated vasodepressor form were excluded. Follow-up lasted 12 +/- 5 months. Symptoms were totally eliminated in 67% of patients and ameliorated with persistence of minor symptoms in 33%. All patients underwent an initial 2-month follow-up in the VVI mode. Evaluation of the 19 patients who remained symptomatic and the 20 who became asymptomatic with VVI pacing demonstrated that factors observed prior to pacemaker implant were related to failure of the VVI mode. These included symptomatic pacemaker effect (42% vs 0%), mixed carotid sinus syndrome (95% vs 65%), orthostatic hypotension (47% vs 15%), or ventriculoatrial conduction (68% vs 38%). In the 23 patients with dual chamber pacing, random 2 month comparisons were performed between VVI and DVI/DDD pacing. The dual chamber mode was preferred by 14 patients, none preferred the VVI mode and nine noted no difference. Comparison of the two groups found that the factors linked to DVI/DDD preference were symptomatic pacemaker effect (50% vs 0%), ventriculoatrial conduction (78% vs 44%), or orthostatic hypotension (50% vs 11%). VVI pacing is efficacious in a high proportion of patients affected by cardioinhibitory or mixed carotid sinus syndrome. The identification of causes of VVI pacing failure allows determination of those who will benefit from VVI pacing and those who should have DVI/DDD. VVI pacing is suggested for the cardioinhibitory type with no symptomatic pacemaker effect and for the mixed type with no symptomatic pacemaker effect or orthostatic hypotension or ventriculoatrial conduction. Dual chamber pacing should be used in all other instances.

Aged↗
PubMed1989

[The choice of stimulation mode in patients with cardioinhibitory or mixed carotid sinus hypersensitivity, with or without associated sinus dysfunction].

In this prospective study, we evaluated pacing therapy in 60 consecutive patients affected by syncopes or pre-syncopes and cardioinhibitory or mixed carotid sinus hypersensitivity. We preferred DDD/DVI pacing for the 26 patients who had: 1) the cardioinhibitory form and presence of symptomatic pacemaker effect, or 2) the mixed type I form and presence of symptomatic pacemaker effect, ventriculo-atrial conduction, or orthostatic hypotension, or 3) the mixed type II form, or 4) the presence of severe sinus bradycardia. We preferred VVI mode in the other 34 patients. Syncope or pre-syncope persisted in one patient of the VVI group after the pacemaker implant and in one patient of the DDD/DVI group. Therefore, we obtained the suppression of severe symptoms in 97% of cases (58/60 pts). Yet minor symptoms persisted in 35% and 38% of patients of the two groups, respectively. No patient developed clinical signs of cardiac insufficiency or intolerance to pacing therapy. Besides, in DDD/DVI patients, we performed a single-blind, randomized, cross-over study for a comparison between the DDD/DVI and VVI mode: each patient was paced for two months using each mode and for each period symptoms were analyzed. The VVI period, compared to the DDD/DVI, resulted in a significantly higher incidence of symptoms: syncope 8% vs. 0%; pre-syncope 31% vs 0%; minor symptoms 58% vs. 31%; cardiac failure 19% vs. 0%. So the DDD/DVI mode was preferred by 69% of the patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

Natural and unnatural history of patients with severe carotid sinus hypersensitivity: a preliminary study.

Natural history of patients with symptomatic severe carotid sinus hypersensitivity is not clearly known. In order to evaluate the effectiveness of pacing therapy in these patients we performed a randomized treatment/no-treatment prospective study in 35 patients. They were randomly assigned to two groups: 19 patients received no therapy, 16 patients received a VVI (#11) or DDD (#5) pacemaker implant. During the 8.4 +/- 4.3 month follow-up period patients receiving no therapy had recurrence of syncope in 9 cases (47%) and minor symptoms in 13 (68%); at the 16th month, actuarial curve showed absence of syncope in 36% of patients and of any symptoms in 30%. During the 7.2 +/- 4.1 month follow-up period, the patients receiving the pacemaker implant had no recurrence of syncope, minor symptoms in three (19%); at the 16th month, actuarial curve showed absence of syncope in 100% of patients and of any symptoms in 78%. During follow-up, 12 patients in no-treatment group received a pacemaker implant because of the recurrence of severe symptoms; successively they had a strong reduction of symptoms. In conclusion, this study definitively demonstrates that patients with severe symptomatic carotid sinus hypersensitivity had a high rate of recurrence of spontaneous symptoms and that in these patients cardiac pacing is a useful therapy.

Aged↗
PubMed1988

Assessment of VVI diagnostic pacing mode in patients with cardioinhibitory carotid sinus syndrome.

In this study, we used Holter pacemakers in a group of 13 patients affected by severe carotid sinus syndrome in order to evaluate its evolution. All the patients had one to three syncopal episodes and frequent other symptoms such as fainting, dizziness, lightheadedness and pre-syncope interferring with their daily activity so that pacemaker therapy was considered necessary. Patient selection criteria were: presence of the isolated cardioinhibitory type, absence of associated sinus dysfunction and absence of symptomatic VVI pacemaker effect. All the patients received a Micropacer 1 device; among special functions, bradycardia events counter was activated and programmed so that each sequence of three consecutive beats at a cycle length 1.5 sec (i.e., 4.5 sec total interval) could be recognized and stored in its memory. The follow-up lasted 13 +/- 7 months. Brady events occurred in eight out of 13 patients (62%), during this period. Syncope and major symptoms disappeared in all the patients; mild dizziness recurred rarely in two patients and were not linked to brady-events recording. In conclusion, disappearance of severe symptoms observed after pacemaker implant in cardioinhibitory carotid sinus syndrome seems to depend from pacing therapy, in most cases, yet from the benign natural course of the disease in some other cases.

Aged↗
PubMed1988

Is DDD superior to VVI pacing in mixed carotid sinus syndrome? An acute and medium-term study.

The aim of this study was to evaluate the importance of atrial synchronism for pacing therapy of patients with mixed carotid sinus syndrome. In 23 patients (21 m, two f; mean age 69 +/- 8 years) affected by symptomatic mixed carotid sinus syndrome we performed: (1) Research of ventriculo-atrial conduction, orthostatic hypotension and pacemaker effect; and (2) Carotid sinus massage in the standing position during VVI and DVI temporary pacing. Next, all patients received a permanent DDD pacemaker and entered a 2 month two period single-blind, randomized, cross-over study on DVI/DDD versus VVI mode. During the DVI/DDD period, no syncope occurred in any patients, minor symptoms persisted in 11 (48%) of them; during VVI period syncopes recurred in three patients, symptoms requiring the withdrawal of VVI pacing and premature DVI/DDD reprogramming in eight patients, minor symptoms in 17 (74%). A comparison between 14 patients, who preferred DVI/DDD period (Group A), and the remaining nine patients who noted no preference between DVI/DDD and VVI period (Group B) was performed on the basis of the preimplant evaluation. Group A patients had a greater pacemaker effect (-34 +/- 16 mmHg vs -16 +/- 14 mmHg) and a higher prevalence of symptomatic pacemaker effect (50% vs 0%), of ventriculo-atrial conduction (78% vs 44%) and of orthostatic hypotension (50% vs 11%), while the entity of the systolic pressure fall caused by carotid sinus massage was similar in the two groups either during VVI mode (Group A -51 +/- 16 mmHg vs Group B -56 +/- 27 mmHg) or DVI mode (Group A -38 +/- 17 mmHg vs Group B -45 +/- 17 mmHg).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

[Comparison of permanent cardiac pacing and cardiac pacing on demand in mixed carotid sinus syndrome. Acute- and medium-term follow-up study].

The aim of the study was to evaluate the importance of atrial synchronism for pacing therapy of patients with mixed carotid sinus syndrome. On 23 patients (21 m, 2 f; mean age 69 +/- 8 years) affected by symptomatic mixed carotid sinus syndrome we performed: 1) the study of ventriculo-atrial conduction, 2) the evaluation of pacemaker effect and 3) the carotid sinus massage in standing position during VVI and DVI temporary pacing. All patients received a permanent DVI pacemaker and then underwent a two-month period single-blind, randomized, cross-over study on DVI vs VVI mode. During DVI period, no syncope occurred in any patients, minor symptoms persisted in 11 (48%) of them; during VVI period syncopes recurred in 3 patients, symptoms requiring the withdrawal of VVI pacing and premature DVI reprogramming in 8, minor symptoms were observed in 17 (74%). A comparison between 14 patients who preferred DVI period (Group A) and the remaining 9 patients who had no preference for DVI and VVI period (Group B) revealed that Group A patients had a greater pacemaker effect (-34 +/- 16 mmHg vs -16 +/- 14 mmHg; p less than 0.02) and a higher prevalence of ventriculo-atrial conduction (78% vs 44%; p = 0.1), while the entity of the systolic pressure fall caused by carotid sinus massage was similar in the two groups both during VVI mode (Group A -51 +/- 16 mmHg vs Group B -56 +/- 27 mmHg) and DVI mode (Group A -38 +/- 17 mmHg vs Group B -45 +/- 17 mmHg).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

[Changes in sinus function at rest and during physical exertion after permanent atrial electrostimulation in patients with sick sinus syndrome].

We studied the unnatural history of sinus node function in severe sick sinus syndrome treated with AAI or DDD pacemakers. In 19 patients (10 m; 9 f; mean age +/- 1 SD 69 +/- 7 years) we executed serial bicycle exercise tests and electrophysiological studies before, 7 days and 3 months after pacemaker implant. Sinus heart rate at maximum effort was: 118 +/- 23 beats/min and 117 +/- 23 beats/min (two different evaluations) before pacemaker implant, 125 +/- 21 beats/min after 7 days (p less than 0.05) and 133 +/- 20 beats/min after 3 months (p less than 0.001) with an average increment of 12.7%. A positive correlation (y = 50.4 + 0.7 X beats/min; p less than 0.001) between the first basal test and the third month one was found. In analogy exercise test lasted 8.7 +/- 3, 8.6 +/- 2.8, 9.5 +/- 2.5, 9.7 +/- 2.5 minutes respectively, with an average increment of 11.5% between the first basal test and the third month one. Sinus heart rate at maximum effort in 14 age matched normal subjects was 138 +/- 15 beats/min. The difference with sick sinus syndrome patients was statistical (p less than 0.05) when compared with the basal test but not with 3rd month test. Parameters determined during electrophysiological studies were: spontaneous heart rate, corrected sinus node recovery time, sino-atrial conduction time evaluated before and after autonomic blockade (propranolol 0.2 mg/kg i.v. plus atropine 0.04 mg/kg i.v.). All these parameters, excepting basal corrected sinus node recovery time, improved significantly after pacemaker implant.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1986

The use of atrial pacing to induce atrial fibrillation and flutter.

We studied the clinical and electrophysiological significance of induction of atrial fibrillation or atrial flutter by atrial electrical stimulation. Our atrial fibrillation/flutter induction protocol included incremental atrial pacing up to a rate of 200 beats/min, ramp up to 250 and 300 beats/min, and bursts up to 600 beats/min. The end point was sustained atrial fibrillation/flutter induction (30 sec). We performed a provocative study on 72 subjects previously divided into three groups: the first was the control group; the second comprised patients with spontaneous paroxysmal atrial fibrillation/flutter; the third comprised patients without spontaneous atrial fibrillation/flutter, but with pathologies assumed to put them at risk for atrial fibrillation/flutter. We were unable to induce sustained atrial fibrillation/flutter in the control group, but were able to induce these arrhythmias in 95% of the subjects with spontaneous atrial fibrillation/flutter. Thus the methods have a sensitivity of 95% and a specificity of 100%. We were also able to induce atrial fibrillation/flutter in 57% of patients at risk for atrial fibrillation/flutter, that is a lower incidence than patients with spontaneous episodes. When sustained atrial fibrillation/flutter could be induced, it was well tolerated and stopped spontaneously in less than 24 hours without treatment. The technique thus involves no risk and demonstrates that antiarrhythmic therapy is usually superfluous in interrupting induced atrial fibrillation/flutter.

Adult↗
PubMed1986

Noninvasive serial electrophysiological testing using an implanted pacemaker for management of recurrent ventricular tachycardia.

An implanted multiprogrammable pacemaker capable of performing both premature and burst stimulation can be teamed with a special external programmer for noninvasive electrophysiological testing. Such studies, combined with indications from provocative pharmacologic tests, allowed us to formulate effective antiarrhythmic therapies for three patients suffering from post-infarction, recurrent sustained ventricular tachycardia.

Aged↗
PubMed1986

[Cardioinhibitory carotid sinus hypersensitivity in subjects with symptomatic sinus dysfunction].

Cardioinhibitory carotid sinus hypersensitivity is present in about one third of patients affected by sinus dysfunction. Aim of the study was to evaluate whether carotid sinus hypersensitivity is related to a well defined (intrinsic or extrinsic) sinus node damage. Fifty-four patients with ecg signs of sinus dysfunction underwent an electrophysiological study and carotid sinus massage. Spontaneous heart rate and corrected sinus node recovery time were measured in basal condition, after adrenergic blockade (propranolol 0.2 mg/Kg i.v.) and after autonomic blockade (propranolol 0.2 mg/Kg i.v. plus atropine 0.04 mg/Kg i.v.). The association between sinus dysfunction and cardioinhibitory carotid sinus hypersensitivity was found in 18/54 pt. (16 men, 2 women; mean age +/- 1 SD 63.6 +/- 14.5 years). The remaining 36 patients (19 men, 17 women; mean age +/- 1 SD 65.8 +/- 9.8 years), affected by sinus dysfunction alone, were used as controls. No electrophysiological differences between the two groups were found; particularly, an abnormal intrinsic heart rate (according to Jose values) or an abnormal intrinsic corrected sinus node recovery time (greater than 385 msec.) were present in 83% of the patients in both groups. Among sinus dysfunction clinical features, heart rate, presence of spontaneous syncope, sino-atrial block or sinus arrest and organic heart disease were similar in the two groups while the percentage of patients with spontaneous atrial tachyarrhythmias (bradi-tachy syndrome) was significantly smaller (11% vs 44%; p less than 0.01) in carotid sinus hypersensitivity group. In conclusion, in sinus dysfunction patients, the presence of carotid sinus hypersensitivity cannot be used as a criterion to differentiate a subgroup with peculiar clinical and electrophysiological sinus node characteristics.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

[Intermittent atrio-ventricular block induced by exertion. Description of 3 cases].

Three patients with 1:1 atrio-ventricular conduction at rest developed fixed 2nd or 3rd degree atrio-ventricular block during exercise testing. In all patients electrophysiologic study documented block distal to the atrioventricular node. The exercise induced block probably occurred because of increased atrial rate and abnormal refractoriness of the His-Purkinje conduction system. These findings suggest that high degree atrioventricular block appearing during exercise reflects conduction disease of the His-Purkinje system rather than of the atrio-ventricular node, even in absence of bundle branch block. These patients should be considered for permanent cardiac pacing.

Adult↗
PubMed1985

Transposition of posterior leaflet for treatment of ruptured main chordae of the anterior mitral leaflet.

A 13-year-old girl with mitral regurgitation resulting from rupture of multiple chordae of the anterior leaflet had repair by transposition of a part of the posterior leaflet to the free edge of the anterior mitral cusp. Postoperative clinical hemodynamic, and angiographic studies showed perfect function of the mitral valve. This technique seems to be a good solution for mitral repair in the presence of ruptured anterior mitral chordae.

Adolescent↗