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Biomedical subjects

Michele Brignole

Publications and source records attributed to Michele Brignole.

At least 37 records · Page 2Linked to original sources
PubMed2005

Neurally-mediated syncope.

"Neurally-mediated (reflex) syncope" refers to a reflex response that, when triggered, gives rise to vasodilation and/or bradycardia; however, the contribution of each of these two factors to systemic hypotension and cerebral hypoperfusion may differ considerably. The initial evaluation may lead to a certain diagnosis in the case of classical vasovagal syncope and of situational syncope. Classical vasovagal syncope is diagnosed if precipitating events such as fear, severe pain, emotional distress, instrumentation or prolonged standing, are associated with typical prodromal symptoms. Situational syncope is diagnosed if syncope occurs during or immediately after urination, defecation, cough or swallowing. In the absence of a certain diagnosis, absence of cardiac disease, long history of syncope, syncope after sudden unexpected unpleasant sight, sound or smell, prolonged standing at attention or crowded, warm places, nausea and vomiting, post-prandial and post-exercise state suggest a neurally-mediated cause which needs to be confirmed by specific tests. Among them, the most useful are carotid sinus massage and tilt testing. In general, education and reassurance are the sufficient initial treatment. Additional treatment may be necessary in high-risk or high-frequency settings. Treatment is not necessary in patients who have sustained a single syncope and are not having syncope in a high-risk setting. It is valuable to assess the relative contribution of cardioinhibition and vasodepression before embarking on treatment as there are different therapeutic strategies for the two aspects. Even if evidence of utility of such an assessment exists only for the carotid sinus massage, it is recommended to extend this assessment also by means of tilt testing or implantable loop recorder. Tilt training and isometric leg and arm counterpressure maneuvers are indicated in patients with recurrent vasovagal syncope. Cardiac pacing is indicated in patients with cardioinhibitory or mixed carotid sinus syndrome and in patients with cardioinhibitory vasovagal syncope with a frequency > 5 attacks per year or severe physical injury or accident and age > 40 years. The evidence fails to support the efficacy of any drug.

Cardiac Pacing, Artificial↗
PubMed2005

Two unusual cases of coincident atrioventricular nodal reentrant tachycardia and ventricular tachycardia.

The simultaneous occurrence of narrow and wide QRS complex tachycardias was observed in 2 patients evaluated at our electrophysiological centers. Electrophysiological testing revealed the coexistence of two types of arrhythmia (atrioventricular nodal reentrant tachycardia and verapamil-sensitive left ventricular tachycardia) in one patient and of three types of arrhythmia (atrioventricular nodal reentrant tachycardia, ventricular tachycardia originating from the right ventricular outflow tract, and left ventricular tachycardia) in the other. Both patients underwent successful radiofrequency ablation of all the types of tachycardia.

Aged↗
PubMed2004

Outcome after cavo-tricuspid isthmus ablation in patients with recurrent atrial fibrillation and drug-related typical atrial flutter.

This study evaluates the long-term clinical outcome of 56 consecutive patients affected by atrial fibrillation and drug-related typical atrial flutter who underwent cavo-tricuspid isthmus radiofrequency ablation. Symptomatic arrhythmic events recurred after ablation in 64% of the patients during follow-up of 19 +/- 9 months. Even in those who had recurrences, there was a substantial reduction in the incidence of episodes, quality of life was improved, and hospitalizations decreased.

Aged↗
PubMed2004

Left ventricular mechanics during right ventricular apical or left ventricular-based pacing in patients with chronic atrial fibrillation after atrioventricular junction ablation.

OBJECTIVES: The aim of the study was to evaluate whether left ventricular (LV) mechanics are better under LV-based pacing than under right ventricular (RV) apical pacing in patients with permanent atrial fibrillation (AF) after atrioventricular junction (AVJ) ablation. BACKGROUND: "Ablate and pace" is an acceptable therapy for drug-refractory AF. However, the RV apical stimulation commonly used seems to interfere with the beneficial hemodynamic effect of regularization of heart rhythm. METHODS: The study included 12 patients (5 men, mean age 62 +/- 8.3 years), 6 with impaired and 6 with normal LV systolic function. All of them had a biventricular pacemaker system implanted and underwent atrioventricular node ablation for drug-refractory chronic AF. Using a conductance catheter, we analyzed LV pressure-volume loops during routine coronary angiography in order to evaluate short-term changes in LV mechanics during RV apical and LV-based (LV free wall or biventricular) pacing. RESULTS: Compared with RV pacing, LV-based pacing significantly improved the indexes of LV systolic function (i.e., end-systolic pressure and volume, cardiac index, stroke work, preload recruitable stroke work, maximal rate of rise of LV pressure [dP/dt(max)], LV ejection fraction, and end-systolic elastance). The LV diastolic filling indexes, end-diastolic pressure and volume, were better during LV-based pacing, whereas LV diastolic function indexes, -dP/dt(max), passive diastolic chamber stiffness, and time constant of LV isovolumic relaxation showed no clear change. CONCLUSIONS: In the short term, LV-based pacing is superior to RV apical pacing in terms of contractile function and LV filling after AVJ ablation for drug-refractory AF.

Atrial Fibrillation↗
PubMed2004

Acute comparative effect of right and left ventricular pacing in patients with permanent atrial fibrillation.

We tested the hypothesis that left ventricular (LV) pacing is superior to right ventricular (RV) apical pacing in patients undergoing atrioventricular (AV) junction ablation and pacing for permanent atrial fibrillation. The potential benefit of LV over RV pacing needs to be evaluated without the confounding effect of other variables that can influence cardiac performance. An acute intrapatient comparison of the QRS width and echocardiographic parameters between RV versus LV pacing was performed within 24 h after ablation in 44 patients. Both modes of pacing were also compared with pre-implantation values. Compared with RV pacing, LV pacing caused a 5.7% increase in the ejection fraction (EF) and a 16.7% decrease in the mitral regurgitation (MR) score; the QRS width was 4.8% shorter with LV pacing. Similar results were observed in patients with or without systolic dysfunction and/or native left bundle branch block, except for a greater improvement in MR in the latter group. Compared with pre-ablation measures, the EF increased by 11.2% and 17.6% with RV and LV pacing, respectively; the MR score decreased by 0% and 16.7%; and the diastolic filling time increased by 12.7% and 15.6%.Rhythm regularization achieved with AV junction ablation improved EF with both RV and LV pacing; LV pacing provided an additional modest but favorable hemodynamic effect, as reflected by a further increase of EF and reduction of MR. The effect seems to be equal in patients with both depressed and preserved systolic functions and in those with and without native left bundle branch block.

Aged↗
PubMed2004

Incidence, diagnostic yield and safety of the implantable loop-recorder to detect the mechanism of syncope in patients with and without structural heart disease.

AIM: To evaluate the incidence, diagnostic yield and safety of implantable loop recorders (ILRs) in patients with or without structural heart disease (SHD). METHODS AND RESULTS: Two-hospitals, observational, prospective study in consecutive patients with unexplained syncope who underwent an ILR implantation. Between November 1997 and December 2002, a total of 2052 patients with syncope were evaluated (referral population of 590000 inhabitants). The diagnosis remained unexplained in 371 (18%). Of these, 103 patients (5% of total, 28% of unexplained syncope) received an ILR. SHD was present in 38 (37%), and absent in 65 (63%). During a median follow-up of 13 months, syncope was recorded in 52 patients. While patients with and without SHD had similar incidence of syncope recurrence, its mechanism was different. Patients with SHD more frequently had paroxysmal AV block and tachyarrhythmias and patients without SHD more frequently had sinus bradycardia/sinus arrest or no arrhythmia. More patients with SHD finally received an ILR-guided therapy. Sudden death occurred in one patient with SHD. Five syncope-related injuries were noted in 3 patients. CONCLUSION: The mechanism of syncope is different in patients with and without SHD; diagnostic yield and safety are similar in both groups. About 28% of patients with unexplained syncope have an indication to ILR implantation. The need for ILR implantation in the general population is 34 implants/million inhabitants/year.

Aged↗
PubMed2004

A randomized, double-blind, placebo-controlled study of permanent cardiac pacing for the treatment of recurrent tilt-induced vasovagal syncope. The vasovagal syncope and pacing trial (SYNPACE).

AIMS: Recently, some studies revealed the efficacy of pacemaker implantation in decreasing recurrences in patients with vasovagal syncope. As these studies were not blinded or placebo-controlled, the benefits observed might have been due to a bias in the assessment of outcomes or to a placebo effect of the pacemaker. We performed a randomized, double-blind, placebo-controlled study in order to ascertain if pacing therapy reduces the risk of syncope relapse. METHODS AND RESULTS: Twenty-nine patients (53 +/- 16 years; 19 women) with severe recurrent tilt-induced vasovagal syncope (median 12 syncopes in the lifetime) and 1 syncopal relapse after head-up tilt testing underwent implantation of a pacemaker, and were randomized to pacemaker ON or to pacemaker OFF. During a median of 715 days of follow-up, 8 (50%) patients randomized to pacemaker ON had recurrence of syncope compared to 5 (38%) of patients randomized to pacemaker OFF (p = n.s.); the median time to first syncope was longer in the pacemaker ON than in pacemaker OFF group, although not significantly so (97 [38-144] vs 20 [4-302] days; p = 0.38). There was also no significant difference in the subgroups of patients who had had a mixed response and in those who had had an asystolic response during head-up tilt testing. CONCLUSION: Our data were unable to show a superiority of active pacing versus inactive pacing in preventing syncopal recurrence in patients with severe recurrent tilt-induced vasovagal syncope.

Cardiac Pacing, Artificial↗
PubMed2004

Clinical spectrum of neurally mediated reflex syncopes.

AIMS: The clinical features of the various types of neurally mediated reflex syncope have not been systematically investigated and compared. We sought to assess and compare the clinical spectrum of neurally mediated reflex syncopes. METHODS AND RESULTS: Four hundred sixty-one patients with syncope were prospectively evaluated and 280 had neurally mediated reflex syncope. Each patient was interviewed using a standard questionnaire. A cause of syncope was assigned using standardized diagnostic criteria. Typical vasovagal syncope was diagnosed in 39 patients, situational syncope in 34, carotid sinus syncope in 34, tilt-induced syncope in 142 and complex neurally mediated syncope (positive response to both carotid sinus massage and tilt test) in 31. The clinical features of situational, carotid sinus, tilt-induced and complex neurally mediated syncope were very similar. By contrast, typical vasovagal syncope differed from other neurally mediated syncopes not only in terms of its precipitating factors (fear, strong emotion, etc.), which constituted predefined diagnostic criteria, but also in the variety of its clinical features (lower age and prevalence of organic heart disease, higher prevalence of prodromal symptoms, and of autonomic prodromes, longer duration of prodromes, higher prevalence of symptoms during the recovery phase and lower prevalence of trauma). CONCLUSION: The clinical spectrum of neurally mediated reflex syncopes demonstrates much overlap between them. However, when the afferent neural signals are localized in cortical sites, as in typical vasovagal syncope, symptoms are more frequent and of longer duration.

Adult↗
PubMed2004

Efficacy of tilt training in the treatment of neurally mediated syncope. A randomized study.

Recurrent neurally mediated syncope represents a common clinical event and a therapeutic challenge. Recently tilt training has been proposed for the treatment of recurrent neurally mediated syncope. To evaluate the efficacy of tilt training in preventing tilt-induced syncope and its feasibility, this controlled, randomized study was undertaken. Sixty-eight consenting patients (25 males and 43 females, mean age 40 +/- 19) with recurrent neurally mediated syncope and 2 consecutive positive nitroglycerin-potentiated head-up tilt tests were randomized to tilt training (35 patients) or no treatment (controls, 33 patients). The tilt training programme consisted of daily 30-min sessions of upright standing against a vertical wall 6 days a week for at least 3 weeks, until a reevaluation tilt test (3 patients of both groups dropped out). On this third head-up tilt test, 19 (59%) of 32 tilt trained patients and 18 (60%) of 30 controls still had a positive test. Treated patients performed a mean number of 15 +/- 7 sessions (median 16) and only 11 patients (34%) did all the programmed sessions. Only 1 patient (3%) discontinued treatment because of intolerance, while all other patients did not perform tilt training adequately, because of poor compliance. Thus, in our study tilt training was not effective in reducing tilt testing positivity rate in patients with neurally mediated syncope. Because of poor compliance, tilt training appears to be a feasible treatment only for highly motivated patients, but not for the majority of patients with recurrent neurally mediated syncope.

Adult↗
PubMed2004

Efficacy and feasibility of isometric arm counter-pressure manoeuvres to abort impending vasovagal syncope during real life.

AIMS: Isometric arm exercises are able to increase blood pressure during the phase of impending vasovagal syncope. We evaluated their efficacy and feasibility during daily life in a group of 29 consecutive patients affected by vasovagal syncopes. METHODS: The patients were trained to use arm tensing and/or handgrip in case of occurrence of symptoms of impending syncope. RESULTS: During 14+/-6 months of follow-up, 260 episodes of impending syncope were reported by 19 patients; the manoeuvres were self-administered by these patients in 98% of cases and were able to abort syncope in 99.6% of cases. Overall, 5 episodes of syncope occurred in 5 patients (17%), in 4 cases without and in 1 with activation of the manoeuvres. Syncope recurred in 4 (40%) of 10 patients aged >65 years versus only 1 (5%) of 19 patients aged < or =65 years, p=0.03. The non-responders had more episodes of impending syncope than responders (37+/-32 vs 3+/-4, p=0.001). Among 19 clinical variables, age in years was the only significant predictor of syncopal recurrence. No patients had injury or other adverse morbidity related to the relapses. CONCLUSIONS: Isometric arm counter-pressure manoeuvres are able to abort impending vasovagal syncope in most patients aged < or =65 years. Arm counter-pressure manoeuvres are feasible, safe and well accepted by the patients in the daily life.

Adult↗
PubMed2004

[How is syncope studied in the Italian hospitals?].

BACKGROUND: The aim of this study was to evaluate how the main tests for the diagnostic assessment of syncope are currently performed in the Italian hospitals. METHODS: During the early 2003 dedicated questionnaires were administered to about 400 Italian hospitals. About each test information was requested relative to: test protocol, laboratory equipment, patients evaluated during 2002. RESULTS: Eighty-four hospitals answered the questionnaire. A syncope-dedicated ambulatory (at least once a week) was available during 2002 in 59/84 hospitals, and 56 were dependent on the Cardiology Division. Carotid sinus massage was performed either in clinostatic and in orthostatic position in 60 Centers and was repeated after atropine in 15. To define the test positivity, 35 Centers followed the "symptom method". Only 15 Centers performed > 100 procedures during 2002 (range 3-500). Tilt testing was performed in 72 hospitals. A dedicated tilting bed was available in 65 Centers, continuous beat-to-beat pressure measurement in 22. Out of the 72 Centers, 55 followed the so-called "Italian protocol" as the main methodology of the test. Only 17 Centers performed > 100 procedures during 2002 (range 3-500). Adenosine test was performed in 26 hospitals, the median dose of drug was 18 mg (range 6-20 mg); 25 out 26 Centers considered the test as positive when an asystolic pause > or = 6 s was observed. Only 6 Centers performed > 15 procedures during 2002 (range 1-204). An implantable loop recorder was available in 48 Centers. The number of implant procedures during 2002 varied among the Centers from 1 to 22. CONCLUSIONS: A great variability was observed concerning the methodology of each test and the number of procedures performed. Thus, a standardization effort about the methodology of syncope study is still needed by the medical associations.

Adenosine↗
PubMed2003

Mechanism of syncope in patients with positive adenosine triphosphate tests.

OBJECTIVES: We prospectively evaluated the mechanism of syncope in patients with positive adenosine triphosphate (ATP) tests (defined as the induction of atrioventricular [AV] block with a ventricular pause >/=6 s after an intravenous bolus of 20 mg ATP). BACKGROUND: Patients with unexplained syncope tend to have more positive ATP tests results than those without syncope. METHODS: An implantable loop recorder (ILR) was inserted in 36 ATP-positive patients (69 +/- 10 years; 22 women; median of 6 syncopal episodes); 15 of them also had a positive response to tilt testing. RESULTS: During the follow-up of 18 +/- 9 months, 18 patients (50%) had syncopal recurrence and 16 (44%) had an electrocardiographically documented episode: AV block (n = 3: paroxysmal in 2 and permanent in 1), AV block followed by sinus arrest (n = 1), sinus arrest (n = 5), sinus bradycardia <40 beats/min (n = 2), normal sinus rhythm (n = 2), sinus tachycardia (n = 1), rapid atrial fibrillation (n = 1), and ectopic atrial tachycardia (n = 1). Bradycardia was documented in a total of 11 cases (69%), and a long ventricular pause (4 to 29 s) was present in eight cases (50%). All three patients with ILR-documented AV block had previously had a negative tilt test, whereas seven of eight with ILR-documented sinus bradycardia or sinus arrest had previously had a positive tilt test. CONCLUSIONS: In patients with adenosine-sensitive syncope, the mechanism of syncope is heterogeneous, although bradycardia is the most frequent finding. Adenosine triphosphate-induced AV block predicts AV block as the mechanism of spontaneous syncope in only a few tilt-negative patients.

Adenosine Triphosphate↗
PubMed2003

Rhythm versus rate control after ablation and pacing for paroxysmal atrial fibrillation: clinical implications of the PAF 2 trial.

Four recent randomized controlled studies that compared rhythm control versus rate control therapy demonstrated that rate control therapy is an acceptable alternative to rhythm control therapy. The control of heart rate achievable with pharmacologic therapy is imperfect and, in many patients, difficult to obtain. Ablation and pacing therapy offers better control of heart rate than drug therapy. The aim of the PAF 2 trial was to evaluate the effect of antiarrhythmic drug therapy on long-term maintenance of normal sinus rhythm after ablation and pacing therapy and to evaluate the effect of maintenance of normal sinus rhythm on major clinical events, quality of life and cardiac performance and, therefore, to evaluate whether antiarrhythmic drug strategy yields any additional benefit to ablation and pacing therapy. In this multicenter randomized controlled trial, 68 patients with severely symptomatic paroxysmal atrial fibrillation were assigned, after successful atrioventricular junction ablation and pacing treatment, to antiarrhythmic drug therapy with amiodarone, propafenone, flecainide or sotalol and were compared with 69 patients assigned, after successful AV junction ablation and pacing treatment, to no antiarrhythmic drug therapy. Although patients in the antiarrhythmic drug arm had a reduction in the risk of developing chronic atrial fibrillation, there was no clinical benefit beyond that obtained with ablation and pacing alone. On the contrary, antiarrhythmic therapy was associated with more serious adverse clinical events, i.e. episodes of heart failure and hospitalization. This suggests that the control of ventricular rhythm by ablation and pacing has a greater beneficial effect on short-term clinical outcome than the preservation of atrial contraction. Therefore, the results of PAF2 study are consistent with the drug trials comparing rhythm and rate control.

Anti-Arrhythmia Agents↗
PubMed2003

Randomized clinical trials of neurally mediated syncope.

Evidence for therapy of neurally mediated syncope is generally weak. Many drugs have been used for the treatment of vasovagal syncope (beta-blockers, disopyramide, scopolamine, clonidine, theophylline, fludrocortisone, ephedrine, dihydroergotamine, etilefrine, midodrine, clonidine, serotonin reuptake inhibitors, enalapril). In general, although the results have been satisfactory in uncontrolled trials or short-term controlled trials, the majority of long-term placebo-controlled prospective trials have not been able to show a benefit of the active drug over placebo. Only two well-designed double-blind placebo-controlled randomized trials have been performed-one for etilefrine and the other for atenolol-and both were unable to show a superiority of the active drug versus placebo. Four randomized clinical trials of pacing therapy-three positive and one negative-have been performed in patients affected by vasovagal syncope. The relationship between carotid sinus hypersensitivity and spontaneous, otherwise unexplained, syncope has been demonstrated. Cardiac pacing appears to be beneficial in carotid sinus syndrome; its efficacy has been demonstrated by two randomized controlled trials and confirmed by several pre-post comparative studies, one controlled trial, and one prospective observational study. There is evidence and general agreement that cardiac pacing is useful in patients with cardioinhibitory or mixed carotid sinus syndrome. Usefulness of the treatment is less well established and divergence of opinion exists with regard to cardiac pacing in patients with cardioinhibitory vasovagal syncope. The evidence fails to support the efficacy of beta-blocking drugs. As yet there are insufficient data to support the use of any other pharmacologic therapy for vasovagal syncope.

Adrenergic alpha-Antagonists↗