Episode Characteristics

Initiation of episodes
A distinct difference was observed between the timing of the onset of an episode and type of LAF. Adrenergic afibbers had most of their episodes begin during the day, mixed had mostly an evening onset, and episodes for vagal afibbers began most often during the night. This is perhaps not surprising as adrenergic (sympathetic) tone is higher during the day while vagal (parasympathetic) tone predominates during rest and sleep.

LAF episodes among adrenergic afibbers were all initiated by events that tend to increase adrenergic tone such as exercise or emotional or work-related stress. Vagal episodes were initiated by events that increase vagal tone such as rest, sleep, digestion or winding down after exercise. Mixed episodes were initiated by either an increase in adrenergic or mixed tone with no special preference for either one.

About 26% of all vagal afibbers noted that they were more likely to have an episode during the evening or night if they had experienced a stressful day. Prof. Coumel has described this phenomenon as "vagal rebound" and suggests that it may be possible to avoid it by taking a small amount of beta-blocker (atenolol) first thing in the morning if a stressful day or event is anticipated.

Almost two thirds (64%) of all paroxysmal afibbers reported frequent urination at the onset of an episode. This phenomenon was most pronounced among vagal afibbers where 72% experienced it versus 50% in the adrenergic group and 59% in the mixed group. The frequent urination is caused by the release of the diuretic hormone atrial natriuretic peptide (ANP) for the walls of the atria during chaotic beating.

Termination of episodes
Fifty-three per cent of all afibbers had observed that light exercise partway through an episode helped terminate it while 34% felt that resting helped speed conversion to normal sinus rhythm. Vagal afibbers were more likely to find exercise beneficial while adrenergic ones found rest to be more effective. Adrenergic afibbers who had found rest beneficial in terminating episodes actually did have significantly shorter episodes. Afibbers who were able to terminate their episodes with rest tended to be older than those who had found no benefit from rest.

Twenty per cent of all respondents felt that they had more than normal difficulty in sleeping during the nights following an episode. This problem was most pronounced among mixed (22%) and vagal afibbers (20%), but not of major concern among adrenergic afibbers (6%).

Repeated sneezing after the termination of an episode was reported by 5% of paroxysmal afibbers with 11% of adrenergic, 7% of vagal afibbers and none in the mixed group reporting this problem. Sneezing could be an indication of heightened vagal tone.

Pattern to episodes
About one third (35% adrenergic, 33% mixed, 34% vagal) of 142 respondents reported a distinct pattern to their episodes. The average (mean) number of days between episodes was 13 (median: 10, range: 1-42 days). There was no correlation between living a routine life and having episodes at regular rather than random intervals. However, afibbers with a regular pattern to their episodes tended to have more frequent and longer lasting episodes than did afibbers with no pattern. Could it be that afibbers with a regular pattern tend to be exposed continually to an environmental, dietary, or emotional irritant?

There was also a strong negative correlation (not too surprisingly) between the number of days between episodes and the frequency of episodes; i.e. afibbers with a short interval between episodes tended to have more frequent episodes over a 6-month period. There was, however, no correlation between the duration of episodes and the interval between episodes neither for all paroxysmal afibbers nor for drug-free paroxysmal afibbers.

Heart rate during episode
The average maximum heart rate during an episode was 139 bpm (range 55-280) for all paroxysmal afibbers (132 respondents). The minimum was 76 bpm (range 35-140) for 86 respondents.

The average maximum heart rate did not differ between afibbers continuously on antiarrhythmics or beta- blockers and those not on drugs nor was there any statistically significant effect in maximum heart rate between those taking beta-blockers or calcium channel blockers on demand and those that did not. This latter finding is counter-intuitive and needs further investigation.

There was no statistically significant difference in maximum episode heart rate between men and women; however, there was a slight, statistically significant trend for the maximum heart rate to decrease with age. No correlation was observed between maximum heart rate and length of time since first diagnosis of afib; nor was there any correlation between resting heart rate and maximum heart rate during an episode.

Main symptoms during episode
The most common symptom experienced in an afib episode was palpitations. Other symptoms were breathlessness, fatigue, and dizziness. Some afibbers felt more than one of these symptoms.

Health Status of Respondents

I. Cardiovascular Health

Blood pressure and pulse rate
Twelve (7%) of 147 paroxysmal afibbers (1 adrenergic, 4 mixed and 7 vagal) had the persistent form of LAF. The average resting pulse rate for all paroxysmal afibbers was 60 bpm (170 respondents) and the average resting blood pressure readings were 124/76 mm Hg (153 respondents).

Beta-blockers, calcium channel blockers and some antiarrhythmics may influence pulse rate and blood pressure. A table showing pulse rate and blood pressure for afibbers not on any drugs is presented below (83 respondents for pulse rate, 72 for blood pressure).

There were no significant differences between pulse rates or blood pressure of adrenergic, mixed, and vagal afibbers, nor was there any significant differences in these parameters between afibbers taking drugs and those not. However, there was a statistically significant correlation between resting pulse rate and gender with women tending to have higher pulse rates than men. There was also a highly significant inverse correlation (not too surprisingly) between resting pulse rate and level of physical activity with highly active afibbers having lower resting pulse rate than sedentary ones. There was no correlation between resting pulse rate and frequency or duration of episodes.

Systolic blood pressure correlated moderately with the presence of diagnosed hypertension (this correlation is no doubt weakened by the use of antihypertensive drugs) and also with the perceived exposure to emotional or work-related stress. Afibbers who felt stressed had higher systolic blood pressures than those who did not feel stressed.

Diastolic blood pressure correlated weakly with the presence of diagnosed hypertension (this correlation is no doubt weakened by the use of antihypertensive drugs) and also with the perceived exposure to emotional or work-related stress with stressed afibbers having higher diastolic pressures.

Hypertension
Thirty-one paroxysmal afibbers had been diagnosed with hypertension and 3 additional respondents qualified as hypertensive because of a systolic pressure over 140 mm Hg or a diastolic pressure above 90 mm Hg. Thus a total of 20% of all paroxysmal afibbers (171 respondents) had excessively high blood pressure (hypertension).

The prevalence of hypertension was significantly higher among permanent than among paroxysmal afibbers (29% versus 20%). The prevalence of hypertension in the general population varies with age, sex and race. Overall estimates are as follows[1]:

Considering that the average age of all paroxysmal afibbers is 54 years a prevalence of 20% is clearly well below the norm. This is probably a result of the generally high health level and fitness of afibbers. A more speculative reason could perhaps be that the diuretic action of the periodic release of atrial natriuretic peptide (ANP) during afib episodes prevents hypertension from taking hold.

Sixty-five per cent of paroxysmal afibbers used drugs to control their hypertension (60% among adrenergic, 60% among mixed, and 68% among vagal). The most popular drugs were atenolol (Tenormin), diltiazem (Cardizem), quinapril (Accupril), followed by metoprolol (Toprol XL), hydrochlorothiazide, and amlodipine (Norvasc).

There was a strong correlation between age and the presence of hypertension with hypertensive afibbers tending to be significantly older.

Congestive heart failure
Congestive heart failure (CHF) is a serious condition in which the heart is weakened to the point that it can no longer pump sufficient blood to meet the body's requirements for oxygen and nutrients. CHF is a major health problem in the United States and Western Europe where about 10 million people are now affected. CHF is a highly lethal condition with one 1 of 5 patients dying within the first year after diagnosis. The prevalence of CHF increases with age and is about 2% among people aged 40-59 years, over 5% among those aged 60-69, and over 10% in people aged 70 years or older. The prevalence among blacks is at least 25% greater than among whites. The incidence of CHF is twice as high in hypertensives as in people with normal blood pressure and having had a heart attack increases risk by a factor of five[2]. Type 2 diabetes is associated with a two-fold increase in the risk of CHF[3].

Our survey of 66 lone afibbers showed that not a single one had been diagnosed with CHF and only one (a 12- year veteran of permanent afib) had been diagnosed with a left ventricular ejection fraction below 0.35. An LVEF below 0.35 is considered a precursor to CHF. Thus it would seem that lone afibbers are at a particular low risk of developing CHF. This is perhaps not too surprising in view of the fact that lone afibbers are generally healthy and fit and have a low incidence of hypertension and diabetes.

Stroke
Stroke (cerebral infarction, cerebrovascular event) is the third leading cause of death in the United States. It strikes about half a million Americans and kills upwards of 150,000 every year. A stroke involves a sudden interruption of blood flow to the brain. This interruption can be caused by a blood clot (thrombus) or a segment of arterial plaque that lodges in a small artery in the brain (ischemic stroke) or by the rupture of an artery wall (hemorrhagic stroke). An ischemic stroke is sometimes referred to as a "heart attack of the brain". The interrupted blood flow results in brain cells being starved of oxygen; if the interruption last more than 4 or 5 minutes the cells will die and irreversible damage will occur. If the cells that die are the ones that control your speech or your left arm then these functions will become impaired. If enough cells die (massive stroke) then so will you.

The risk of a stroke increases with age; it is estimated that 5% of the population over 65 years of age will suffer a stroke. A prior stroke, heart disease, diabetes, hypertension, atrial fibrillation, high homocysteine levels, and a bacterial infection of the lining of the heart cavity (endocarditis) are significant risk factors. Major surgery accounts for a large number of ischemic strokes. It is estimated that as many as 25,000 people suffer a stroke every year as a sequel to coronary bypass surgery[4-8].

Atrial fibrillation is a risk factor for ischemic stroke because of the inefficient pumping action of the atria during fibrillation. The fibrillating atrium basically sits and quivers like a bowl of jelly. This can cause blood to stagnate and if the fibrillation goes on long enough to coagulate and form blood clots (thrombi). If one of these blood clots finds its way to a small artery in the brain a stroke may result. The danger of this happening is actually highest when the fibrillation ceases. The increased pumping action, once the atria gets back to normal, flushes out the heart chamber and with it any newly formed blood clots. This is why anticoagulation with warfarin (Coumadin) and/or heparin is essential prior to cardioversion and for about 3 weeks after.

Lone atrial fibrillation, by definition, means that there are no underlying heart problems present. So unless you have hypertension, diabetes, are over 75 years of age or have suffered a previous stroke or TIA you are at no greater risk for stroke than the general population[9]. Medical experts are pretty unanimous on this point. Dr. Rodney Falk, MD of Boston University, a world-renowned expert on atrial fibrillation, says that the stroke risk in patients with lone atrial fibrillation is minimal[8]. Professor Michael D. Ezekowitz, MD of the Veterans Administration says, "patients with lone atrial fibrillation are not at higher risk for thromboembolism than the general population and can be managed without anticoagulation or anti-platelet therapy"[10]. Dr. Stephen L. Kopecky of the Mayo Clinic did the first study regarding stroke risk in patients with lone atrial fibrillation. He found that lone afibbers under the age of 60 years had an exceptionally low stroke risk (0.55%) and that this risk varied little whether the fibrillation was paroxysmal or permanent[11].

More recently Canadian researchers evaluated the stroke risk among 2500 atrial fibrillation (non-valvular AF) patients who were treated with a daily aspirin. Twenty-four per cent of the group was considered at low risk for stroke because of the absence of hypertension (systolic blood pressure below 140 mm Hg), no history of stroke or TIA, no symptomatic coronary artery disease, and no diabetes. In this low-risk group the incidence of stroke was 1.0 per 100 person years as compared to 1.2 per 100 person years in an age- and sex-matched group of people with no atrial fibrillation. Low risk patients who were randomized to oral anticoagulation (warfarin) experienced 1.5 strokes per 100 person years. Strokes included both ischemic and hemorrhagic. The researchers conclude, "Irrespective of age, patients with AF and none of the above four clinical features and who take aspirin have stroke rates comparable to those of age-matched community cohorts and would not benefit substantially from anticoagulation."[12]

Our survey included 159 lone afibbers. Not one had suffered a stroke of any kind. Interpretation of this finding must, of course, be approached with extreme caution. Clearly afibbers having suffered a fatal or severely disabling stroke would be unlikely to have participated in the survey. However, there is no reason why afibbers who have suffered a mild stroke or a transient ischemic attack (TIA) should not have participated. A TIA involves a temporary deficiency of blood to the brain. Effects are usually reversible within 24 hours. A TIA is followed by a stroke in about 1 out of 3 cases[13].

A total of 5 TIAs (3 among permanent afibbers) were reported in the survey. These were in a sample covering 1145 person years of exposure (years of afib). So the incidence is 0.4 per 100 person years. Is this normal or abnormal?

Dr. Jerome FX Naradzay of the Samaritan Medical Center estimates a TIA incidence rate of 0.4 to 0.8 cases per 100 person years in the general population aged 50-59 years and a recent study carried out at the Ottawa Heart Institute found a combined stroke rate of 1.0 per 100 person years in afibbers treated with aspirin[12,14].

So overall the TIA rate found in our survey would appear to be fairly normal except in the case of permanent afibbers where the rate was 2.6 per 100 person years. The sample was, however, quite small (15 people) so the results must be taken with a grain of salt. The ages of the 3 permanent afibbers who had suffered a TIA were 59, 63 and 65 years respectively. One was on aspirin or warfarin at the time of the TIA while one was not on stroke prevention medicine. The medication status of the third one is unknown.

Electrolyte levels
Electrolyte levels, that is, the intracellular levels of potassium (K), sodium (Na), magnesium (Mg), and calcium, are important for proper functioning of the heart. Low levels of potassium and magnesium, in particular, may predispose to ectopic beats and afib.

Thirty-seven out of 159 respondents had had their intracellular electrolyte levels checked and 23 (62%) had abnormal levels. Low magnesium levels were found in 6, low potassium in 4, high calcium in 3, and one each of low and high phosphorous levels.

Conclusion
Lone afibbers would appear to have excellent cardiovascular health with normal resting pulse rates, normal blood pressures, and a low incidence of hypertension. There were no cases of congestive heart failure in our survey group (166 afibbers) even though a prevalence of 2-5% would have been expected. No strokes were reported by 159 afibbers (this observation must be viewed with caution as afibbers who have suffered a stroke may be less likely to participate in the survey). There were 5 reported cases of transient ischemic attack (TIA) in the group (3 among permanent afibbers). This is probably in the normal range except among the small sample of permanent afibbers (15 respondents) where the incidence was 2.6 per 100 person years. A majority (62%) of afibbers who had been tested for intracellular electrolyte levels had abnormal levels, most often, low magnesium, low potassium or high calcium. It is not known how this finding compares to what would be expected in the general population.

Our finding that lone afibbers have excellent cardiovascular health supports those made in 1998 by researchers at the University of Helsinki[15]. Their study concluded that men who engaged in long-term vigorous exercise (as many afibbers do) have a 5 times greater risk of developing LAF, but a 3 times lower risk of developing coronary heart disease and 5 times lower overall mortality than less active men.

1. Hypertension prevalence and the status of awareness, treatment, and control in the USA. Hypertension, Vol. 7, 1985, pp. 457-68
2. www.nhlbi.nih.gov/health/public/heart/other/CHF.htm
3. Nichols, GA, et al. Congestive heart failure in type 2 diabetes: prevalence, incidence, and risk factors. Diabetes Care, Vol. 24, September 2001, pp. 1614-19
4. Harrison's Principles of Internal Medicine, 12th edition, 1991, McGraw-Hill, NY, pp. 1977-85
5. Bots, Michiel, L., et al. Homocysteine and short-term risk of myocardial infarction and stroke in the elderly. Archives of Internal Medicine, Vol. 159, January 11, 1999, pp. 38-44
6. Bostom, Andrew G., et al. Nonfasting plasma total homocysteine levels and stroke incidence in elderly persons. Annals of Internal Medicine, Vol. 131, September 7, 1999, pp. 352-55
7. Roach, Gary W., et al. Adverse cerebral outcomes after coronary bypass surgery. New England Journal of Medicine, Vol. 335, December 19, 1996, pp. 1857-63
8. Falk, Rodney H. and Podrid, Philip J., editors. Atrial Fibrillation: Mechanisms and Management, 2nd edition, 1997, Lippincott-Raven, NY, pp. 277-98
9. Gage, Brian F., et al. Validation of clinical classification schemes for predicting stroke. Journal of the American Medical Association, Vol. 285, June 13, 2001, pp. 2864-70
10. Saoudi, Nadir, et al., editors. Atrial Flutter and Fibrillation, 1998, Futura Publishing, Armonk, NY, pp. 229-36
11. Kopecky, Stephen L., et al. The natural history of lone atrial fibrillation. New England Journal of Medicine, Vol. 317, No. 11, 1987, pp. 669-74
12. van Walraven, C., et al. A clinical prediction rule to identify patients with atrial fibrillation and a low risk for stroke while taking aspirin. Archives of Internal Medicine, Vol. 163, April 28, 2003, pp. 936-43
13. Merck Manual of Medical Information (home edition), Simon & Schuster, NY, 1997, p. 382
14. http://emedicine.com/EMERG/topic604.htm
15. Karjalainen, Jouko, et al. Lone atrial fibrillation in vigorously exercising middle aged men: case-control study. British Medical Journal, Vol. 316, June 13, 1998, pp. 1784-85

CLEVELAND, OHIO. A team of American and German cardiologists has evaluated the safety and efficacy of using large oral doses of propafenone (Rythmol) or flecainide (Tambocor) for converting atrial fibrillation to normal sinus rhythm. A total of 107 atrial fibrillation patients were randomized to receive the drugs in a hospital setting (56 patients) or to take the drugs at home without medical supervision (61 patients). The drugs used were 600 mg of propafenone or 300 mg of flecainide both taken with 25-50 mg of metoprolol or 240 mg of slow- release diltiazem. Conversion was achieved in 61% of the in-hospital patients and in 73% of the "do-it-yourself" at-home patients. The most common side effect was a metallic taste in the mouth, but no serious side effects were observed in either of the two groups. The researchers conclude that at-home administration of large doses of propafenone (600 mg) or flecainide (300 mg) together with metoprolol or diltiazem for rate control is just as safe as administration in a hospital setting.
Marrouche, Nassir F., et al. Oral bolus of IC antiarrhythmic drugs for atrial fibrillation: outpatient versus inpatient administration. Journal of the American College of Cardiology, March 19, 2003, p. 98A (abstract)

Editor's comment: I have experienced good results with 225 mg of propafenone plus 12.5 mg of atenolol (Tenormin). I swallow the tablets in crushed form with a little warm water as soon as possible after the onset of an episode. Nevertheless, both propafenone and flecainide are powerful drugs and should not be used for at-home termination without the approval of a cardiologist.

LUDWIGSHAFEN, GERMANY. German cardiologists have evaluated the relative effectiveness of time-release metoprolol (Toprol XL), sotalol (Betapace), and amiodarone (Cordarone) in maintaining sinus rhythm after cardioversion of the first recurrence (second episode) of atrial fibrillation. Their study involved 571 patients of which 161 were treated with metoprolol (47-190 mg/day), 228 with sotalol (160-320 mg/day), and 182 with amiodarone (200 mg/day). About 60% of the patients had some form of organic heart disease, so this was definitely not an experiment involving just lone afibbers. About 70% of the participants were male and the average age of all participants was 62 years. During a follow-up period of 3 years after successful cardioversion 58% of the patients treated with metoprolol experienced another AF episode as compared to 71% in the sotalol group and 70% in the amiodarone group. The researchers conclude that metoprolol XL is more effective than sotalol or amiodarone in maintaining sinus rhythm after successful electrical cardioversion.
Seidl, Karlheinz, et al. Recurrence rate of atrial fibrillation in patients after the first relapse: a comparison between metoprolol CR/XL, sotalol, and amiodarone. Journal of the American College of Cardiology, March 19, 2003, p. 98A (abstract)

Editor's comment: The high percentage of organic heart disease in the group means that most of the participants probably had the adrenergic type of AF. The results obtained are unlikely to apply to vagal afibbers.

BRISTOL, UNITED KINGDOM. NO-ASA or nitric oxide donating aspirin (nitroxy-butyl-acetylsalicylate) is a new class of drugs that shows great promise in reducing the risk of thrombosis (formation of blood clots) after surgical procedures such as coronary artery bypass grafting (CABG). Researchers at the University of Bristol recently concluded that NO-ASA might be useful in preventing thrombosis, vasospasm and vascular smooth muscle cell proliferation after CABG.
Shukla, N., et al. Nitric oxide donating aspirins: novel drugs for the treatment of saphenous vein graft failure. Annals of Thoracic Surgery, Vol. 75, May 2003, pp. 1437-42

Editor's comment: It is possible, but not yet proven, that NO-ASA may also turn out to be an excellent anticoagulant choice for afibbers.

SANTIAGO, CHILE. Atrial fibrillation is associated with an increased stroke risk, particularly among older patients. The stroke risk is associated with the formation of blood clots in the left atrial appendage during fibrillation. Researchers at the Catholic University of Chile have recently completed a study to determine if AF patients have different blood levels of the coagulation activation factor thrombin-antithrombin (TAT) complex. Having an increased level of this factor would aggravate the tendency to form blood clots. Their study involved 53 patients with atrial fibrillation and matched healthy controls. The researchers found that the TAT values for afib patients averaged 40.1 mg/L (median 8.34 mg/L) as compared to 2.7 mg/L in healthy controls. Permanent (chronic) afibbers had higher mean values than did paroxysmal (intermittent) afibbers (49.4 mg/dL versus 29.5 mg/dL). The researchers also noted that patients who had taken antiplatelet agents had a significantly lower TAT value than did those who had not (17.3 m/dL versus 66.8 mg/dL). They conclude that previous antiplatelet treatment prevents a higher activation of the coagulation cascade during afib.
Perez, LA, et al. Hypercoagulability in atrial fibrillation and its relationship with risk factors for systemic embolism. Rev Med Chile, Vol. 130, October 2002, pp. 1087-94 [article in Spanish]

Editor's comment: These findings support the idea that antiplatelet agents such as aspirin, fish oils, vitamin E, vitamin C, vitamin B6, and magnesium are beneficial supplements for afibbers.

RICHMOND, VIRGINIA. The risk of having a stroke during radiofrequency ablation is generally 1-2%, but increases with age. Cardiologists at the McGuire Veterans Affairs Medical Center now warn that having experienced a prior transient ischemic attack (TIA) may significantly increase stroke risk during ablation. Their study involved 56 patients who underwent ablation for paroxysmal atrial fibrillation. The mean procedure time was 4 hours (227 minutes) and 86% of the patients had trigger points in the pulmonary veins. Three of the patients (5%) experienced a cerebrovascular event (stroke) during the procedure; all were over 60 years of age and 2 had experienced a previous TIA.
Kok, LC, et al. Cerebrovascular complication associated with pulmonary vein ablation. J Cardiovasc Electrophysiol, Vol. 13, August 2002, pp. 764-67, 768-69

MAASTRICT, THE NETHERLANDS. A team of Dutch cardiologists reports that cryoablation is safe and effective for the treatment of atrial fibrillation. Their clinical trial involved 43 patients who underwent segmental ablation of the pulmonary veins. The immediate success rate was 98%; however, after 8 months of follow-up only 78% showed improvement and only 52% were completely afib-free. Three patients experienced serious adverse events, but there was no evidence of stenosis as measured with a spiral CT scan 3 months after the procedure.
Rodriguez, Luz-Maria, et al. Beyond radio frequency: new ablation techniques. Journal of the American College of Cardiology, March 19, 2003, p. 91A (abstract)

Editor's comment: It is not clear if all patients had lone afib or not. It is conceivable that the procedure may be more successful in lone afibbers, but, as always, the surgeon's skill is the number one factor in determining success rate.

MADDALONI, ITALY. Electrical remodeling of the atria is an important sequel to atrial fibrillation and increases the risk of future episodes. It is believed that an overload of intracellular calcium is at least partly responsible for the remodeling. Italian researchers now report that AF patients pretreated with verapamil prior to electrical cardioversion tend to remain in sinus rhythm longer than do non-treated patients. Their study involved 88 afibbers who had experienced an early recurrence (within 7 days) after a successful cardioversion. The patients were treated with warfarin for 3 weeks prior to attempting a second cardioversion and continued on their antiarrhythmic drugs (mostly flecainide and amiodarone). Half the group received no other drugs, but the other half received 240 mg of verapamil daily for the 3 days preceding and the 3 days following the electrical cardioversion procedure. The researchers found that 21% of the patients in the verapamil group (21%) spontaneously reverted to normal sinus rhythm (NSR) prior to the scheduled cardioversion; only two patients (4%) in the non-verapamil group experienced spontaneous conversion. During 3 months of follow-up 26 patients (30%) experienced another AF episode, but the incidence was lower in the verapamil group (19% versus 40%). It is also worth noting that the average number of ectopic beats experienced by the verapamil group was significantly lower than in the non-verapamil group (145 versus 177 ectopic beats per hour).
De Simone, Antonio, et al. Effect of verapamil on secondary cardioversion in patients with early atrial fibrillation recurrence after electrical cardioversion. American Journal of Cardiology, Vol. 90, July 15, 2002, pp. 185-87

Editor's comment: There would seem to be little to lose and much to gain by asking your cardiologist to put you on 240 mg/day of verapamil for 3 days prior to and 3 days following a scheduled electrical cardioversion.

BALTIMORE, MARYLAND. Implantable cardioverter-defibrillators (ICDs) are increasingly used for arrhythmia control, especially in patients with life-threatening arrhythmias. There is no clear consensus as to whether antiarrhythmic drugs, beta-blockers, or no drugs should be used in conjunction with the ICD. Researchers at the Johns Hopkins University recently discovered that patients discharged from hospital on amiodarone or sotalol (Class III antiarrhythmics) had a 47% higher risk of dying within an average 5.5-year follow-up than did patients discharged on Class I drugs (propafenone, flecainide, etc.) or on no drugs at all. Those discharged on beta- blockers did best with a 56% reduction in mortality when compared to patients on no drugs. The results were obtained after adjusting for other variables that could affect mortality. The researchers conclude that the use of beta-blockers may be associated with a significant survival advantage while the use of Class III antiarrhythmics may be detrimental in patients with ICDs.
Tandri, Harikrishna S., et al. Antiarrhythmic agents may decrease long-term survival in patients with implantable defibrillators. Journal of the American College of Cardiology, March 19, 2003, p. 96A (abstract)

TAIPEI, TAIWAN. It is known that the local renin-angiotensin system (RAS) in the heart plays an important role in atrial fibrillation. Taiwanese researchers now report that afib patients have significantly different RAS genes than do people without AF. The study involved 110 AF patients and 110 matched controls. The researchers found that the frequencies of M235T, G-6, and G217 allele were significantly higher in afib patients and that these higher frequencies were associated with an increased risk of AF. They conclude that angiotensin converting enzyme (ACE) inhibitors or angiotensin II antagonists may be useful in the treatment of AF.
Tsai, Chia-Ti, et al. Significant association of renin-angiotensin system gene polymorphisms with human atrial fibrillation. Journal of the American College of Cardiology, March 19, 2003, p. 90A (abstract)

FUKUOKA, JAPAN. There is considerable evidence that atrial fibrillation is associated with an inflammation of the heart tissue and accompanying elevation of the level of the inflammation marker, C-reactive protein (CRP). Japanese researchers have found that atorvastatin (Lipitor), a cholesterol-lowering drug, shortens the duration of afib episodes induced in dogs. They suggest that atorvastatin may be a novel therapeutic agent for afib.
Nakashima, Hideko, et al. The HMG-CoA reductase inhibitor atorvastatin prevents atrial fibrillation in inhibiting inflammation in the canine sterile pericarditis model. Journal of the American College of Cardiology, March 19, 2003, p. 90A (abstract)