Rehabilitation in post-COVID patients. A single center experience

 

The COVID 19 disease is frequently associated with significant disability related to intensive care unit-acquired weakness, decontitioning, myopathies and neuropathies. However there are no data on the results of a specific rehabilitative treatment in this group of patients.

The aim of our work was to evaluate the effectiveness f a personalized rehabilitative therapy in group of post-COVID patients (A, 47 patients, average age 65.3±11.6 y, 27 M,) comparing the results with a group of post-cardiosurgical patients COVID 19 negative (B, 47 patients, average age 63.5±10.3 y, 29 M) evaluating the degree of clinical complexity (Rehabilitation Complexity Scale, RCS-E V13) and the degree of autonomy recovery (Six-minute walking test SMWT, Barthel Index, BI) pre and post-treatment.

In Group A patients the Rehabilitation program is associated with a significant improvement in autonomy recovery (BI admission 29.7±20 vs discharge 72.7±28.6 p<0.005, SMWT admission 146±25 vs 318±18 m, p<0.005) and in clinical complexity (RCS admission 10.9±1.1 vs discharge 5.3, p<0.05).

At admission the comparison between Group A vs B has show:

1. a reduced pre-rehabilitation hospital stay (days) in Group Vs A (B 8.2±2 vs 31±5 0.005)

2. a similar degrre of clinical complexity (RCS scale A 10.9±1.1 vs 1.6±11.2 p ns)

3. a greater loss autonomy in post-COVID patients (BI scale A 29.7±20 vs B 47.7±19, p 0.05; SMWT A 145±25 m vs B 255±18 m, p 0.05)

After a similar period of rehabilitation (A 29.7±12.8 days vs B 29.6±10 days, p ns) we observed in both Groups:

1. a reduction of clinical complexity ((RCS scale A 5.3±2 vs 6.6±2 p ns

2. an improvement of degree of autonomy recovery ((BI scale A 72.7±28 vs B 47.7±19, p ns; SMWT A 385±18 m vs B 410±25m, p ns)

Conclusions

Post-COVID patients show a greater loss of autonomy than post-cardiosurgery patients. Rehabilitative treatment has proven effective in ensuring adequate functional recovery with similar results to those obtained in the population of cardiological subjects COVID 19 negative.

Funding Acknowledgement

Type of funding sources: None.

Effectiveness of rehabilitation in post-COVID compared with post-cardiosurgery patients. A single Center experience

Funding Acknowledgements

Type of funding sources: None.

The COVID 19 disease is frequently associated with significant disability related to intensive care unit-acquired weakness, decontitioning, myopathies and neuropathies. However there are no data on the results of a specific rehabilitative treatment in this group of patients.

The aim of our work was to evaluate the effectiveness f a personalized rehabilitative therapy in group of post-COVID patients (A, 47 patients, average age 65.3± 11.6 y, 27 M,) comparing the results with a group of post-cardiosurgical patients COVID 19 negative (B, 47 patients, average age 63.5± 10.3 y, 29 M) evaluating the degree of clinical complexity (Rehabilitation Complexity Scale, RCS-E V13) and the degree of autonomy recovery (Six-minute walking test SMWT, Barthel Index, BI) pre and post-treatment.

In Group A patients the Rehabilitation program is associated with a significant improvement in autonomy recovery (BI admission 29.7 ± 20 vs discharge 72.7 ± 28.6 p <0.005, SMWT admission  146 ± 25 vs 318 ± 18 m, p <0.005) and in clinical complexity  (RCS admission 10.9 ± 1.1 vs discharge 5.3, p< 0.05)

Conclusions

Post-COVID patients show a greater loss of autonomy than post-cardiosurgery patients. Rehabilitative treatment has proven effective in ensuring adequate functional recovery with similar results to those obtained in the population of cardiological subjects COVID 19 negative.

P1555 Delta mapse: an easy-to-use tool to evaluate coronary artery stenosis during dypiridamole pharmacological stress echocardiography

Background

Dypiridamol stress echocardiography (DSE) is an important tool for detecting reversible ischemia in patients with suspected coronary artery disease (CAD); nonetheless the results of the test are related to visualization of wall motion abnormalities, moderately operator-dependent, and left anterior descending (LAD) artery reserve, resulting in a moderate sensibility and specificity. Aim of our study was to evaluate whether an an easy-to-use parameter like mitral annular plane systolic excursion (MAPSE) could be useful to identify CAD during DSE.

Methods

We prospectively enrolled 300 patients with suspected CAD and perform a DSE; at rest and peak MAPSE was acquired. 59 patients with reversibile ischemia during stress echocardiography (positive) were referred to perform coronary angiography. Patients were divided according to MAPSE behaviour during DSE: group 1 (MAPSE ≤ 0) and group 2 (delta MAPSE &gt; 0 mm).

Results

The mean age of was 63 ± 11 years, male gender was prevalent (73%); no differences were found in risk factors and left vetnricular ejection fraction (LV-EF) between two groups.Coronary arteries were normal in 14 patients (23%), while significant stenosis (&gt;70%) was found in 45 patients (77%); in 31 patients (53%) left main (LM) or proximal LAD artery were involved, while in 17 (29%) and 22 (37%) right coronary artery and circumflex artery were affected respectively. Patients with CAD showed a lower (blunted or no increase) MAPSE after dypiridamole infusion, with a significative difference in Delta Mapse (Mapse peak-Mapse rest) between groups (0,2 mm vs 2,8 mm p = 0,004) (Figure 1B). By using a Receiver Operating Curve, the Area under the curve was 0,757, with the best cut-off value for CAD prediction at Delta Mapse= +2.5 mm (sensibility 0,667 and specificity 0,809 – p = 0.012 - Figure 1b). In particular, Delta Mapse was able to predict LM/LAD stenosis (Figure 1B AUC = 0.679 ;p = 0.019), rather than right coronary artery and circumflex artery disease, with higher predictivity than delta LV-EF (AUC = 0.577; p = 0.077).

Discussion

To our knowledge, this is the first study that compared the behaviour of MAPSE during dypiridamole infusion in patient with and withouth coronary artery disease. MAPSE is a well-known surrogate of longitudinal systolic function and have increased sensitivity over traditional methods of systolic performance such as LV-EF; in this context, dypiridamole induced reversible ischemia could affect prematurely MAPSE then EF or wall motion abnormalities. In our study, in patients with evidence of reversible ischemia during DSE, a blunted or no increase of MAPSE was able to predict CAD, mostly driven by LM/LAD disease, on top of other well known markers of ischemia. Incorporating this easy-to-use parameter could improve specificity of DSE and strenghten the suspect of reversibile ischemia when clear wall motion abnormalities are not found.

Abstract P1555 Figure 1A and 1B

P1317 Very late onset of platypnoea orthodeoxia syndrome as first clinical scenario of patent foramen ovale

Top

Scintigraphy with ventilation and perfusion lung scan sequences. Next, scintigraphy with capitation of Tc-99m macro aggregated albumin in brain, thyroid and kidneys.

Bottom, Transesophageal echocardiogram: images taken within the same heart beat proving right-to-left passage of bubble across the septum.

Abstract P1317 Figure. Scintigraphy and Transesophageal echo

P2875Comparison between ejection fraction, global longitudinal strain, mechanical dispersion and delta contraction duration in predicting first and subsequent arrhythmic events in ICD patients

Background

According to current guidelines, left ventricular ejection fraction (LVEF) is currently the most important parameter for primary prevention of sudden cardiac death in patients with structural heart disease. Unfortunately, LVEF has low sensitivity in detecting arrhythmic events and presents a significant intra- and inter-operator variability. For these reasons, alternative predictors in patients with structural heart disease are being sought. Among those, speckle-tracking derived parameters such as global longitudinal strain (GLS), mechanical dispersion (MD), and delta contraction duration (DCD) have been proposed as better alternatives.

Purpose

To assess speckle-tracking derived parameters as predictors of first and subsequent arrhythmic events in implantable cardioverter-defibrillator (ICD) patients with structural heart disease, and to compare their performance with LVEF.

Methods

Prospective, observational study enrolling all consecutive patients with structural heart disease admitted for an ICD implant. Patients not followed by a home-monitoring system were excluded. 2D speckle-tracking analysis was used to derive GLS, MD, and DCD of all patients at enrolment. Home monitoring was checked weekly in order to detect all ventricular arrhythmias (VA) and ICD therapies. A recurrent-event statistical approach (Prentice, Williams, and Peterson model) was applied in order to evaluate subsequent events after the first ones.

Results

Two-hundred-and-three patients were consecutively enrolled and followed-up for a median follow-up of 2.2 years. Kaplan-Meier curves showed an increased risk of ATP or shock (Log-rank p=0.003) and VAs (Log-rank p=0.001) associated with lower quartiles of GLS (Figure 1). An impaired GLS was independently associated with an increased risk for the first ICD therapy (HR 1.94; 95% CI 1.30–2.91; p=0.001), and for the first VA (HR 1.42; 95% CI 1.01–1.98; p=0.04). GLS impairment was not significantly associated with an increased risk of recurrent ICD therapies or VAs. LVEF, MD and DCD were not associated with an increased risk of first, second and third ICD therapy or VA.

Conclusions

Impaired GLS is associated with an increased risk of VAs and appropriate ICD therapies in a consecutive, “real-world”, unselected population of remote-monitored patients with structural heart disease, although it does not seem reliable in predicting further arrhythmic event after the first one. LVEF, MD, and DCD do not predict first or subsequent arrhythmic events in ICD patients with structural heart disease.

Acknowledgement/Funding

Marche Polytechnic University

Multidisciplinary and multisetting team management programme in heart failure patients affects hospitalisation and costing

BACKGROUND

We evaluated whether multidisciplinary disease management programme developed with collaboration of physicians and nurses inside and outside general district hospital settings can affect clinical outcomes in heart failure population over a 12-month period.

METHODS

571 patients hospitalised with CHF were referred to our unit and 509 patients agreed to participation. The intervention team included physicians and nurses from Internal Medicine and Cardiac Dept., and the patient's general practitioners. Contacts were on a pre-specified schedule, included a computerised programme of hospital visits and phone calls; in case of NYHA functional class III and IV patients, home visits were also planned.

RESULTS

The median age of patients was 77.7+/-9 years (43.3% women). At baseline the percentage of patients with NYHA class III and IV was 56.0% vs. 26.0% after 12 months (P<0.05). Programme enrolment reduced total hospital admissions (82 vs. 190, -56%, P<0.05), number of patients hospitalised (62 vs. 146, 57%, P<0.05). All NYHA functional class benefited (class I=75%, class IV=67%), with reduction in the costing (-48%, P<0.05). Improvement in symptoms (-9.0+/-3.2) and signs (-5.2+/-3.1) scores was measured (P<0.01). Therapy optimisation was obtained by 20.5% increase in patients taking betablockade and 21.0% increase in those on anti-aldosterone drugs.

CONCLUSIONS

Multidisciplinary approach to CHF management can improve clinical management, reducing hospitalisation rate and costing.

Biventricular pacing in patients with heart failure and intraventricular conduction delay

In patients with advanced chronic heart failure, characterized by prolonged QRS duration and by decreased cardiac contractility, decreasing dysynchrony by biventricular pacing seems to improve exercise tolerance (6-min walk distance), symptoms (New York Health Association class), and quality of-life scores. Although the results of several reports were consistent, the numbers of patients studied were small, and many of the changes were trends that did not reach statistical significance. The availability of a non-pharmacological treatment that improves exercise capacity and quality-of-life would be a major advance. However, further studies will need to address the question of mortality and morbidity benefits of such intervention.

[Prognostic value of supraventricular arrhythmias in heart failure]

Supraventricular tachyarrhythmias can be responsible for severe hemodynamic derangement which may contribute to the progression and worsening of heart failure. The resultant effect of these arrhythmias, however, is conditioned by several concomitant factors, such as age of the patients, left ventricular systolic function, and ventricular rate response. If the role of such arrhythmias in functional class, morbidity, and functional capacity is well accepted, controversial data are available on their role on mortality in patients with heart failure.

Emerging concepts in exercise training in chronic heart failure

There are objective similarities between heart failure and muscular deconditioning. Deficiencies in peripheral blood flow and skeletal muscle function, morphology, metabolism and function are present. The protective effects of physical activity have been elucidated in many recent studies: training improves ventilatory control, metabolism and autonomic nervous system. Exercise training seems to induce its beneficial effects on the skeletal muscle both directly (on function, histological and biochemical characteristics) and indirectly by reducing the activation of the muscle neural afferents (ergoreceptors). On this basis a skeletal muscle origin of symptoms in heart failure has been proposed. The possible metabolic mediators of ergoreceptors are currently being under investigation and they could be a possible target of therapy in heart failure symptoms.

Effects of diltiazem pretreatment on direct-current cardioversion in patients with persistent atrial fibrillation: a single-blind, randomized, controlled study

BACKGROUND

Electric conversion of atrial fibrillation is the most widely used and effective treatment for sinus rhythm restoration. However, it has a limited success rate and a high recurrence rate.

HYPOTHESIS

Pretreatment with calcium channel blocker may improve the efficacy by reversing the so-called "electric remodeling" phenomenon, also related to overload in cytosolic calcium.

METHODS

The efficacy of diltiazem or amiodarone pretreatment (oral, 1 month before and 1 month after conversion) on direct-current conversion of persistent atrial fibrillation was assessed in 120 patients, randomly assigned to 3 matched groups: A (n = 44, diltiazem); B (n = 46, amiodarone), and C (n = 30, digoxin).

RESULTS

Before electric conversion, all treatments significantly decreased mean heart rate. Spontaneous conversion to sinus rhythm was achieved in 6% of patients of group A (3 of 46) versus 25% of group B (11 of 44) and 3% (1 of 30) of group C (A/C vs B, P < .005). Current conversion was more successful in group B (91%) compared with group A (76%) and group C (67%) (B vs A/C, P < .05), with no difference in the electric threshold for effective conversion (P = not significant). At the 24-hour time point, early relapse of atrial fibrillation was similar between groups A and B (A, 2%; B, 3%; P = not significant) and lower than group C (12%) (P < .01), whereas at the 1-month time point the recurrence rate was lower in group B (28%) versus groups A (56%) and C (78%) (B vs A/C, P < .01). No significant side effects were reported.

CONCLUSIONS

Although diltiazem seems to be as effective as amiodarone in reducing early atrial fibrillation recurrences, diltiazem is less effective in determining spontaneous or electric conversion, with a higher recurrence rate at 2 months. Diltiazem pretreatment could be considered as only a second choice treatment in those patients in whom amiodarone is contraindicated.

[Changes in the cardiac rhythm in ischemic cardiopathy]

Ventricular arrhythmia associated with ischemic heart disease has an important role in the etiology of sudden death, both in acute and chronic coronary syndromes. The etiopathogenesis of ventricular arrhythmia is strictly linked to the time-course from the occurrence of coronary occlusion. In the very acute phase of the ischemia, ventricular arrhythmias are due to a reentry mechanism, while 4-8 hours after occlusion the enhanced automatism, and triggered activity are the key mechanisms. Therefore reentry mechanisms are the main factors responsible for postinfarction arrhythmias. Also autonomic mechanisms, electrolytes and pharmacological therapy may contribute to cause arrhythmias.

The role of EP-guided therapy in ventricular arrhythmias: beta-blockers, sotalol, and ICD's

Arrhythmic death can be reduced by antiarrhythmic drugs to a range of 24%. Electrophysiologic study by testing noninducibility of ventricular arrhythmia represents the classic method for evaluating the effectiveness of drug therapy. Several clinical studies have shown thaat sotalol suppresses VT induction and prevents arrhythmias recurrences at long term follow-up in 23% to 67% of patients. The efficacy of sotalol EP guided therapy in preventing VT/VF is not necessarily related to prevention of sudden death. In the ESVEM study the superiority of d,l-sotalol to other antiarrhythmic drugs was confirmed. The response to programmed ventricular stimulation was found to be strongly predictive for arrhythmia free state while the failure of sotalol therapy to suppress VT at the EP study was associated with an high recurrence rate (40%). However, EP study failes to predict freedom from sudden death. The beta-blocking activity of racemic sotalol may account for some of the observed survival benefit.Beta-blockers therapy reduces mortality in patients after myocardial infarction primarily by a reduction of sudden death. A reduction of death, worsening heart failure and life threatening ventricular arrhythmias was shown in a recent study on carvedilol. In the prospective study of Steinbeck the EP guided-therapy did not improve the overall outcome when compared to metoprolol. Suppression of inducible arrhythmias by antiarrhythmic drugs was associated with a better outcome. The effectiveness of defibrillator therapy in reducing overall mortality, has been uncertain since great clinical trials have been concluded. MADIT, AVID and CASH trials confirmed the superiority of ICD therapy over antiarrhythmic drugs therapy: ICD should be considered the first choice therapy in post-cardiac arrest patients. The ongoing BEST Trial will give us further responses about the interaction between EP study and metoprolol effect compared to ICD in patients post myocardial infarction also focusing on tolerability and compliance of the beta-blocking therapy in patients with low ejection fraction. In this study will be useful to optimize therapy in patients at high risk of sudden death.

Oral amiodarone increases the efficacy of direct-current cardioversion in restoration of sinus rhythm in patients with chronic atrial fibrillation

AIMS

Direct current cardioversion of persistent atrial fibrillation is one of the most widely used and effective treatments for the restoration of sinus rhythm, but may be hampered by a low success rate and a high percentage of early recurrence. Pre-treatment with amiodarone or a glucose-insulin-potassium solution could improve the efficacy of electrical cardioversion by reversing the partially depolarized diastolic potential of the subsidiary pacemakers in atrial fibrillation. In a controlled randomized study, we assessed the effectiveness of electrical cardioversion in patients with persistent atrial fibrillation after pre-treatment with amiodarone or potassium infusion and the efficacy of amiodarone in maintaining sinus rhythm after electrical cardioversion.

METHODS AND RESULTS

Ninety-two patients with persistent atrial fibrillation (>2 weeks duration) were prospectively randomized into three matched groups: A (n=31, oral amiodarone 400 mg. day(-1)1 month before and 200 mg. day(-1)2 months after cardioversion), B (n=31, 180 mg. day(-1)oral diltiazem 1 month before and 2 months after cardioversion and 80 mmol potassium, 50 UI insulin in 500 ml 30% glucose solution 24 h before cardioversion) and C (n=30, control patients, 180 mg. day(-1)oral diltiazem 1 month before and 2 months after cardioversion). Before cardioversion all patients were under 4 weeks effective oral anticoagulant therapy (warfarin). Before electrical cardioversion, the rate of spontaneous conversion to sinus rhythm was higher in group A (25%) than groups B (6%) or C (3%) (P<0.005). Electrical cardioversion was more successful in group A (88%) than groups B (56%) or C (65%) (P<0.05), while the electrical thresholds for effective cardioversion were lower in group B than the other groups (P<0.05). Twenty-four hours after cardioversion, the early recurrence of atrial fibrillation was similar in the three groups (P=ns), while at 2 months the recurrence rate was lower in group A (32%) than groups B (56%) or C (52%) (P<0.01).

CONCLUSION

Pre-treatment with low-dose oral amiodarone, compared with oral diltiazem or glucose-insulin-potassium treatments, induces a significantly high percentage of instances of spontaneous conversion, increases electrical cardioversion efficacy and reduces atrial fibrillation recurrence.

Comparison of therapy detection times between implantable cardioverter defibrillators with standard dual- and single-chamber pacing

Previous implantable cardioverter defibrillators (ICDs) required patients in need of dual-chamber (DDD) pacing for improved hemodynamic status to undergo implantation of separate devices to treat bradycardia and/or ventricular arrhythmias. An investigation was conducted to verify the performance of a new ICD that combines both therapies.Sixty-nine patients at 17 European and Canadian centers were implanted with VENTAK AV models 1810/1815, ICD's that includes DDD pacing and algorithms designed to differentiate between atrial and ventricular arrhythmias. 36 of the cohort were compared to 32 patients tested at six centers with an external test device (VENTAK MINI). In both cohorts detection times were calculated for ventricular fibrillation (VF) induced at implant. The mean detection times (DT) from the VENTAK AV device were compared to the DT from the VENTAK MINI device. Patient characteristics of the VENTAK AV and the VENTAK MINI control groups were similar. Mean VF detection time (+/-SD) with the VENTAK AV device was 2.21 +/- 0.54 seconds, as compared with 1.87 +/- 0.62 seconds with the VENTAK MINI (p < 0.01), indicating that the difference in means did not exceed one second. The VENTAK AV system function did not demonstrate interaction with the pacemaker function, as indicated by the clinical significance with the detection times of the study device. The difference in detection times between cohorts did not statistically exceed one second. Appropriate detection of the new ICD was not compromised by the addition of the dual-chamber pacing therapy.

Clinical potential of emerging antiarrhythmic agents

Analyses of randomised clinical trials have suggested that only in selective populations may antiarrhythmic drugs be effective in improving prognosis: therapy of cardiac arrhythmias, in contrast to other cardiovascular pathological conditions, has not been fully successful. The ideal treatment of arrhythmias should be guided by a sound understanding of the relative arrhythmogenic mechanisms and vulnerable parameters of the different arrhythmias. New model agents are pure class III agents, developed to fulfil these ideal characteristics and are now under active investigation (dofetilide, ibutilide, azimilide, ambasilide, E 4031, almokalant, sematilide, RP 58866 and tedisamil).

Capture window in human atrial fibrillation: evidence of an excitable gap

INTRODUCTION

Local capture of atrial fibrillation (AF) was shown in animal experiments for a wide range of pacing rates, thus demonstrating the existence of an excitable gap. The aim of this study was to assess the existence of an excitable gap in human AF by studying the mechanism of local control and acceleration of AF over a wide range of pacing rates and by evaluating the time window of capture.

METHODS AND RESULTS

Recording and stimulation of electrical activity in the right atrium during AF was performed by a monophasic action potential (MAP) contact electrode catheter in 17 patients with lone AF during electrophysiologic study. Stimulation was started at pacing intervals close to the mean AF interval, and the time window of capture was estimated by lengthening or shortening the pacing interval until capture was lost. Pacing intervals shorter than the minimum cycle length for capture were also tested. Beat-to-beat measurements of AF intervals during pacing were performed. Atrial MAP signal showed rapid irregular activity with an average AF interval of 151.3 +/- 16.1 msec and SD of 21.3 +/- 5.2 msec. Rapid pacing with a cycle length slightly shorter or longer than the mean AF interval resulted in local capture of AF. The width of time window of capture ranged from 22 to 36 msec, with a mean value of 28.8 +/- 4.9 msec. The average minimum pacing interval of stable capture was 129.2 +/- 19.5 msec, while the maximum was 158.1 +/- 18.7 msec, corresponding to 85% and 104% of mean AF cycle length, respectively. Pacing too rapidly resulted in a transient acceleration of AF, with an average shortening of fibrillation interval from 149.8 +/- 16.6 to 123.2 +/- 15.1 msec (P < 0.01).

CONCLUSION

Local capture is feasible during AF in humans over a wide range of pacing rates, indicating the possibility of regional control of the fibrillatory process. This result demonstrates the presence of an excitable gap during AF in human atria.

Safety of oral propafenone in the conversion of recent onset atrial fibrillation to sinus rhythm: a prospective parallel placebo-controlled multicentre study

AIM

Oral propafenone is effective in restoring sinus rhythm however the proarrhythmic effects are still unknown. The Safety Antiarrhythmic Therapy Evaluation (SATE) trial was a prospective randomized placebo-controlled multicentre study which evaluated the safety of acute oral loading dose of propafenone in patients with recent onset atrial fibrillation. Secondary end-points were to evaluate the effect of digitalis added to propafenone in ventricular rate control and the efficacy of propafenone alone or added to digitalis compared with efficacy of digitalis plus quinidine.

METHODS AND RESULTS

246 patients (126 male; 58+/-11 years) with atrial fibrillation of <48 h duration were randomly allocated to one of four groups: digitalis 0.75-1 mg i.v. plus quinidine 1100 mg (D+Q, 70 patients); propafenone 450-600 mg orally (PNF, 66 patients); propafenone 450-600 mg orally plus digitalis 0.750-1 mg i.v. (PNF+D, 70 patients); placebo (Pl, 40 patients). All patients underwent 24-h ECG Holter monitoring. Safety was assessed by evaluating the appearance of adverse events classified as mild, moderate and severe. No severe adverse events were reported. Short lasting asymptomatic atrial flutter episodes with atrio-ventricular conduction > or =2:1 were observed in 14% of the D+Q group, 21% PNF, 18% PNF+D and in 8% Pl. One patient in the D+Q group and four in the PNF+D group showed asymptomatic runs of 3-4 ventricular ectopic beats. Reversible sinus atrial blocks (<3 s) were detected in two patients of the D+Q group and in two of the PNF group. In patients with persistent atrial fibrillation the ventricular rate was similar in the four study groups. At 3 h the high efficacy of propafenone was confirmed. At the 24th hour no differences were found between active treatment and placebo arms.

CONCLUSION

Propafenone in a single oral loading dose is safe and promptly effective in patients with recent onset atrial fibrillation.

The role of oral 1C antiarrhythmic drugs in terminating atrial fibrillation

Antiarrhythmic drug therapy still remains the mainstay in the management of many supraventricular and ventricular arrhythmias. Several studies have recently pointed out the role of orally administered class 1C drugs in terminating atrial fibrillation. These drugs can play an important role in the ambulatory management of selected patients. The electrophysiologic mechanisms of these antiarrhythmic drugs together with their pharmacologic properties and clinical indications are discussed according to the current literature.

Overview and meta-analysis of randomised trials of amiodarone in chronic heart failure

Unlike other antiarrhythmic class I drugs, amiodarone showed in preliminary studies, benefits also in patients with left ventricular dysfunction. These positive results have induced the development of large randomised controlled studies: their results are reviewed and the controversial points are discussed. In a meta-analysis of randomised controlled trials the use of amiodarone in heart failure was associated with an approximate 20 to 25% reduction in deaths. However, amiodarone was also associated with a 120 to 124% increase in side effects.

Effects of Class III drugs on atrial fibrillation

The Class III antiarrhythmic drugs have been used for the treatment of atrial fibrillation (AF); however, each has specific electrophysiologic properties that delineate different safety and/or effectiveness profiles. First-generation Class III agents seem to be more effective in preventing recurrence of AF than in converting AF to sinus rhythm. The high incidence of major cardiac and noncardiac side effects in the long term often requires discontinuation of the chronic antiarrhythmic therapy. The second-generation Class III drugs, ibutilide and dofetilide, have demonstrated interesting clinical applications, especially in the setting of atrial flutter. However, their favorable antiarrhythmic effect is counterbalanced by the high incidence of severe proarrhythmias. New promising experimental data suggest that the new Ikr-ks blockers may be free from these dangerous limitations, thus extending the indication of Class III drugs in the treatment of AF.

Clinical pharmacology of antiarrhythmic drugs

Antiarrhythmic drugs play a major role in the management of the most common types of arrhythmias. The margin between the beneficial and toxic effects of these drugs is often narrow. Thus, a precise knowledge of dosages, drug-target tissue interactions, pharmacodynamics and pharmacokinetics of antiarrhythmic drugs is needed to better predict how effective a particular drug will be in the treatment of a specific arrhythmia in a given patient. Despite the large amount of information that is available on the electrophysiological and pharmacological effects of antiarrhythmic drugs, we still do not know enough about their true mechanism of action in individual patients. The results of the Cardiac Arrhythmia Suppression Trial (CAST) firmly established that the use of class I drugs is potentially dangerous in a specific subset of patients. Additionally, several meta-analyses have reported that quinidine has severe proarrhythmic effects in patients with atrial fibrillation. The management of arrhythmias in elderly patients is difficult because of age-related factors that may influence the pharmacokinetics and pharmacodynamics of antiarrhythmic drugs.

Risk of complications of atrial fibrillation

Atrial fibrillation is associated with three major risk of complications: thromboembolism, hemodynamic compromise, and arrhythmogenesis. In patients with chronic atrial fibrillation the incidence of embolization is about 5% per year. The risk of embolism and in particular of stroke can be reduced by warfarin anticoagulation. Aspirin is generally less effective than warfarin, although it is probably more effective than placebo. The hemodynamic complications which may occur during atrial fibrillation are mainly due to the loss of effective atrial contraction, the irregular ventricular rhythm, and the possible excessively rapid ventricular rate. Sudden death is a recognized manifestation of Wolff-Parkinson-White syndrome and is considered to be precipitated by atrial fibrillation in the majority of patients. Torsades de pointes is perhaps the most widely recognized proarrhythmia associated with treatment of atrial fibrillation, especially with 1A antiarrhythmic drugs and sotalol. The chronic treatment with type 1C drugs in 3.5%-5% of patients may induce atrial flutter with 1:1 conduction with significant hemodynamic compromise.

Steroid-eluting electrodes prevent chronic pacing threshold rise in the atrial chamber after oral propafenone administration

The aim of the study was to evaluate chronic atrial pacing threshold increase after oral propafenone therapy. Fifty patients affected by advanced AV block and sick sinus syndrome were studied at least 6 months after pacemaker implantation, before and after oral propafenone therapy (450-900 mg/day based on body weight). The patients were subdivided into three groups as to the type of electrode implanted, all three unipolar: group I (20 patients) Medtronic CapSure 4003, group II (13 patients) Medtronic Target Tip 4011, group III (17 patients) Medtronic 4057 screw-in leads. In all cases, Medtronic unipolar pacemakers were implanted with the same noninvasive autothreshold measurement method. Propafenone and 5-OH-propafenone blood levels were measured 3-5 hours after drug administration. The packing autothreshold was measured at 0.8, 1.6, and 2.5 V by reducing the pulse width. After propafenone, groups II and III showed a statistically significant threshold rise (P ranging from < 0.01 to 0.05), whereas no significant difference was found in group I. Propafenone and 5-OH-propafenone blood vessels did not show any significant difference among the three groups. Strength-duration curves were drawn for the three groups before and after propafenone: at baseline the curves shifted to the left with the steep part above the knee, clearly favoring CapSure over the other two groups. After propafenone, the curves shifted to the right, with the flat par progressively more evident in groups II and III. In the atrial chamber, steroid-eluting leads prevented threshold increase after propafenone therapy, in contrast with a significant threshold rise with conventional porous and screw-in leads.

[Epidemiology and therapy of atrial fibrillation]

Atrial fibrillation (AF) is the most common supraventricular arrhythmia in the Western world and its prevalence increases with age. The objectives of the pharmacologic treatment of AF are mainly three: to restore sinus rhythm, to maintain sinus rhythm, and to control ventricular rate during AF. Class 1C antiarrhythmic drugs (propafenone, flecainide) have been demonstrated to be the most effective drugs in restoring sinus rhythm with low risk/benefit and cost/benefit ratios and percentage efficacy rate between 50% and 60%. The long-term efficacy of antiarrhythmic therapy for preventing AF recurrences is far from ideal. Different studies have reported unsatisfactory results with class 1C, class III (sotalol) and class 1A (quinidine, diisopyramide) antiarrhythmic drugs. Calcium channel blockers (diltiazem, verapamil) alone or in combination with digitalis are the drugs of choice in ventricular rate control. New pharmacologic approaches may be hypothesized based on the experimental evidence of 5-hydroxy-triptamine receptors in human atria. Non pharmacologic attempts introduced for AF therapy include: pacemaker implantation, catheter ablation, surgical procedures, internal defibrillation. Atrial fibrillation in patients with tachycardia-bradycardia syndrome is an important indication for permanent pacing. With the advent of dual chamber stimulation it has become apparent that atrioventricular sequential pacing may be superior to VVI pacing in patients with sick sinus syndrome where it may prevent the development of chronic AF. Catheter ablation of atrioventricular node is an accepted approach in patients with drug refractory AF, in patients with sick sinus syndrome where pacemaker therapy failed to prevent paroxysmal AF, or in patients with ICD in order to avoid inappropriate DC-shock. Surgical interventions for AF aim at maintaining sinus rhythm by confining the arrhythmia within the left atrium (left atrial isolation technique) or to both left and right atrium (corridor technique). Another procedure (maze) consists of multiple incisions in the right and left atrium. Recently internal low energy cardioversion has been demonstrated to be effective in treating AF in animal models, and initial clinical studies have shown it can be useful in cardioverting chronic AF in humans as well, suggesting the potential usefulness of an implantable cardioversion device in clinical practice.

Therapeutic options for malignant ventricular tachyarrhythmias: is the implantable cardioverter-defibrillator a primary alternative or merely complementary?

In considering alternatives to the implantable cardioverter-defibrillator (ICD) in patients with malignant ventricular arrhythmias, both pharmacologic and nonpharmacologic therapies are available. Unfortunately, both pharmacologic methods (even when therapy is individualized and optimized) and nonpharmacologic methods (including coronary revascularization and radiofrequency or surgical ablation) yield long-term results that are unacceptable for many patients. Thus, the ICD should be strongly considered as complementary therapy, even when alternative methods are selected. More importantly, early implantation of an ICD often may be justified as the first therapeutic alternative, rather than as complementary therapy, in patients with life-threatening ventricular arrhythmias.

P-wave dispersion index: a marker of patients with paroxysmal atrial fibrillation

The P-wave triggered signal-averaged ECG (PSA-ECG) has shown controversial results in the evaluation of patients with paroxysmal atrial fibrillation (PAF). Previously tested PSA-ECG parameters, i.e. P-wave filtered duration (Pd), root mean square voltage of the last 20 ms of the P-wave vector magnitude (RMS20) were compared with an index of P-wave dispersion (PDi = Pd (X, Y, Z lead) S.D./mean value x 100) in the evaluation of 40 subjects (24 M, 54 +/- 7 years) with or without PAF, without anti-arrhythmic therapy. Patients presented vs. controls higher Pd values (138 +/- 14 ms vs. 120 +/- 12 ms, P < 0.0005), PDi (8 +/- 2 ms vs. 1 +/- 1 ms, P < 0.0001) but no difference in RMS20. In the comparison of patients vs. controls, Pd > or = 125 ms presented 62% sensitivity and 78% specificity, PDi > or = 5.5 ms showed 83% sensitivity and 81% specificity: the combination of these two criteria differentiated a subgroup of patients with no recurrence of PAF in a 12 +/- 4 months follow-up PDi and Pd could be powerful criteria in the identification of patients and could be able to identify patients with low recurrences of PAF.

Atrial late potentials in patients with paroxysmal atrial fibrillation detected using a high gain, signal-averaged esophageal lead

High gain, signal-averaged ECGs using conventional surface lead technique and a transesophageal lead technique were performed in 45 idiopathic paroxysmal atrial fibrillation patients and in 33 normal controls. Both techniques showed increased P wave duration in patients compared with the controls (P < 0.001), but higher P wave amplitudes were obtained using the transesophageal technique compared with surface leads (patients: 169.8 +/- 81.7 microV vs 15.8 +/- 7.3 microV; P < 0.0005; controls: 163.5 +/- 22.1 microV vs 18.5 +/- 5.2 microV; P < 0.0005). The signal-averaged transesophageal lead, but not the surface recordings, identified the presence of atrial late potentials evidenced by lower root mean square voltages in the terminal portion of the P wave: in last 10 seconds, 4.4 +/- 1.3 microV versus 8.5 +/- 3.0 microV; P < 0.001; in last 20 seconds, 7.0 +/- 2.3 microV versus 16.0 +/- 7.9 microV; P < 0.001; in last 30 seconds, 12.5 +/- 5.3 microV versus 23.8 +/- 12.8 microV; P < 0.001, in patients with respect to controls. The criterion P wave duration > or = 110 msec had 85% sensitivity, 100% specificity, and 100% positive predictive value in identifying the patients; the combined criteria P wave duration > or = 110 msec and root mean square for the last 10 msec < or = 6.5 showed 80% sensitivity, 100% specificity, and 100% predictive value. The signal-averaged transesophageal lead produces a higher amplitude signal, which reveals fractionation of atrial activation in atrial fibrillation and allows identification of individuals predisposed to this arrhythmia.

Cardiac pacing in unilateral left superior vena cava: evaluation by digital angiography

In a patient with complete heart block and chronic lymphocytic leukemia a pacemaker lead could not be introduced from either the right or left subclavian vein. Digital subtraction angiography excluded a neoplastic mediastinal mass, demonstrated a unilateral left superior vena cava and defined the best route for lead insertion.

[The efficacy of oral treatment with flecainide for paroxysmal atrial fibrillation: correlation with plasma concentration]

In the acute treatment of paroxysmal atrial fibrillation several drugs can be used. The aim of our work was to assess the efficacy of a single oral dose of flecainide in the conversion to sinus rhythm by correlating this data with flecainide plasma concentration. We have considered 37 patients affected by paroxysmal atrial fibrillation (for more than 8 hours) randomly assigned to the following two groups: group A, 19 patients, mean age 44.4 +/- 1.9 years) treated with flecainide (200 mg) and control group B (18 patients, mean age 46.6 +/- 1.8 years). This was done in order to point out any possible overlap between pharmacological and spontaneous conversion to sinus rhythm. In all patients, the following were performed: a Holter recording (524 hours) to evaluate the time of conversion to sinus rhythm (t-conversion to sinus rhythm), a determination of flecainide plasma concentration (after 150 flecainide administration) an Rx, an Echo-2D/Doppler test and an estimation of thyroid function. The Rx, the Echo-2D/Doppler and the endocrinological data in the 2 groups did not show any significant differences. We obtained a conversion to sinus rhythm in all but one of the group A patients (time of conversion to sinus rhythm 162 +/- 83 min) and in just 5 group B patients (time of conversion to sinus rhythm 1118 +/- 125 min) (time of conversion to sinus rhythm A vs B p less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)

[Early peak of CPK in acute myocardial infarct: a marker of clinical instability?]

The evaluation of the CPK-peak time (CPK-p) during Acute Myocardial Infarction (AMI) is now considered as a reliable method to identify ischemic myocardial tissue reperfusion both spontaneous and pharmacologically-induced. The purpose of this study is to assess the clinical significance of this index over a non selected group of patients (pts) affected by a first episode of AMI looking for some variables possibly connected with it. This study includes 114 pts hospitalized in our Unit Coronary Care (UCC) and diagnosed as affected by AMI and not treated with anticoagulant and/or fibrinolytic drugs. They were divided according to CPK-p into 2 groups: group A (23 pts, 18M 5F, mean age 64.2 +/- 10.1y; CPK-p 11.9 +/- 3.3h, AMI Anterior 14/AMI Inferior 9) and group B (91 pts, 85M 6F, mean age 64 +/- 10.3y; CPK-p 25.7 +/- 4.5h, AMI Anterior 50/AMI Inferior 41). Moreover, a third group C has been studied including pts with similar clinical characteristics who underwent thrombolysis by intravenous infusion of Streptokinase (48 pts, 39M 9F, mean age 62.7 +/- 10.6y; CPK-p 15.2 +/- 7h, AMI Anterior 28/AMI Inferior 20). For each pt CKP-p has been evaluated as well as the pre-UCC time (T-pc), the maximum value of released CPK (CPK-max), the incidence of new coronary events such as angina, re-AMI, sudden death detected between the 1st (NEC-I) and the 6th month (NEC-II) after the acute event.(ABSTRACT TRUNCATED AT 250 WORDS)