40 L& 4 2 .-z .4
30
20
10
E 2
0
Jan Feb Mar Apr MayJuaeJuly AugScp Ott Nov Dee
FIGURE 1. The number of admissions for acute atrial fibrillation (AF) per month, the value of monthly alcohol sales in millions of Finnish marks (mFmk) and the mean monthly air temperature in degrees of Celsius from January to December
1999.
proposed, but there are scattered data to indicate that exposure to cold may precipitate ventricular dysrhythmias both in health and in disease.5F6 Epidemiologic studies have shown that morbidity and mortality from coronary heart disease manifest seasonal variation with a
Risk Factors for Atrial Grafting
Fibrillation
Lance H. Crosby, RN, MS, W. Bradley Pifalo, and John A. Burkholder, MD
MD,
trial fibrillation (AF) and other supraventricular tachyarrhythmias have been shown to occur in alA most 30% of patients who have undergone coronary artery bypass grafting (CABG).ie3 Causes may include
From the Cardiac Rehabilitation Department, 490 East North Avenue, Suite 102, Pittsburgh, Pennsylvania 1.5212. Manuscript received June 6, 1990; revised manuscript received and accepted July 25,199O.
1520
THE AMERICAN JOURNAL OF CARDIOLOGY VOLUME 66
peak in winter and a trough in summerin cold and temperate zones.3,4This pattern is reminiscent of the one found in the presentstudy, which suggeststhat the basic underlying mechanismsmay be similar. Our investigation has certain limitations that should be consideredin the interpretation of the data. The study was hospital-based and therefore the occurrence of asymptomatic or nonsustainedepisodesof AF could not be assessed.The data should be otherwiserepresentative, however,becauseour hospital is by far the largest referral center in the province of Uusimaa and also becausepatients contacting private doctors or community health centers for acute-onsettachyarrhythmias are, as a rule, sent to the hospital in our area. We could not ascertain whether the size of the population at risk remained constant throughout the study period. It is extremely unlikely, however, that changes in the population size could explain the variation in admissionsfor AF, becausesimilar variation was not found in the number of all emergency admissionsfor medical reasons.In fact, the rate of all medical admissions was lowest in the first third of the year, when the number of admissionsfor AF washighest. The value of alcohol salesin our provincewasthe only indicator available to us of monthly variation in alcohol consumption by the local population. It had a direct and temperature-independent linear relation to the rate of admissionsfor AF. Even though this associationdid not quite reach the conventional limit of statistical significance, and although the value of alcohol sale is not a perfect surrogate for the real volume of ethanol consumed,we think that thesedata are in reasonableharmony with the concept of alcohol as a risk factor for AF.2,4 1. Alpert JS, PetersenP, GodtfredsenJ. Atria1 fibrillation: natural history, complications and management.Ann Reu Med 1988;39:41-52. 2. Koskinen P, Kupari M, LeinonenH, LuomanmSkiK. Alcohol and new-onset atria1fibrillation: a case-controlstudy of a current series,Br Heart J 1987;57:468473. 3. Vuori I. The heart and the cold. Ann ChinRes 1987;19:156-162. 4. Anonymous.Alcohol and atria1 fibrillation (editorial). Lancet 1985;1:1374.
5. DeBacker G, Jacobs DR Jr, Prineas RJ, Crow RS, Kennedy H, Vilandre .I, Blackburn H. Ventricular prematurebeats:screeningand induction tests in normal men. Cardiology 1980;65:23-41. 6. Lader EW, Kronzon I. Ice-water-inducedarrhythmias in a patient with ischemit heart disease.Ann Intern Med 1982;96:614-615.
After Coronary
Artery
Bypass
Kathleen R. Wall, RN, MS,
direct surgical trauma to the atria1 conductive network, postoperative irritative pericarditis, abrupt P-blocker withdrawal or inadequateatria1protection during cardiopulmonary bypass.4Risk factor profiles for the development of AF after CABG have been compiled without a consistentpattern emerging.5,6The purposeof this study was to evaluate possiblecontributing risk factors for the developmentof AF in a large cohort of patients immediately after CABG.
TABLE
II Operative Characteristics Groups Nonsupraventricular Tachyarrhythmia (n = 205)
I I I
Prospective analysis of consecutive patients immediately after elective CABG were studied. Patients undergoing concomitant cardiac procedures such as left ventricular aneurysm resection, valve repair or replacement, septal defect repair, and so forth, were excluded before the study. Patients with preexisting valvular heart disease or congestive heart failure also were excluded. The anesthetic and surgical techniques were similar for all patients. Patients who experienced an episode of sustained supraventricular tachyarrhythmias postoperatively were grouped for study. Sustained supraventricular tachyarrhythmias were defined as episodes lasting 130 seconds; however, most were persistent, necessitating antiarrhythmic therapy. All patients were maintained on a heart rhythm monitor with arrhythmia detection capabilitiesfor X5postoperative days. The usual hospitalization period was 7 to 9 days. Patients who had postoperative complications such asperioperative Q-wave myocardial infarction, thoracic reexploration and clinical pericarditis were identiBed and analyzed separately. Clinical pericarditis was diagnosed by an audible pericardial friction rub after the removal of all chest tubes, associated symptomatology and treatment with anti-inflammatory agents. Patients with a prior history of atria1 dysrhythmias but normal sinus rhythm at the time of surgery or previous coronary revascularization were also evaluated separately. The remaining population was divided into the supraventricular and nonsupraventricular tachyarrhythmia groups. Factors analyzed to detect differences between groups were (I) preoperative characteristics: age, gender, history of myocardial infarction; and (2) operative characteristics: number of grafts, aortic cross-clamp time, creatine kinase peak, hemoglobin and hematocrit on the third postoperative day and complications during and after surgery. The study data were analyzed with descriptive statistics including mean f standard deviation, andfrequency distributions. Student’s t and chi-square statistics were used to test the statistical significance of group differences. The hospital course of 418 consecutive patients admittedfor elective CABG were followed. Sustainedpostoperative supraventricular tachyarrhythmias occurred in 122patients (29%). Of these, AFoccurred in 85% (n = 104), followed by undefined in 9% (n = I I) and atria1 flutter in 6% (n = 7). Reviewing this group for incidence ofsupraventricular tachyarrhythmias and the following conditions-previous CABG, history of preoperative AF, clinical pericarditis and perioperative myocardial
Creatine kinase
*standard deviation. TThird postoperative NS = not significant.
Supraventricular Tachyarrhythmia (n = 86)
p Value
41(13)9
40(16)
NS
10(l)
9 (2)
NS
29 (3)
27 (5)
NS
763 (607)
877 (824)
NS
2.5 (1)
2.5 (1)
NS
day.
infarction-we found that there were no statistical differences between or among conditions (Table I). After controlling for these conditions, 291 subjects remained. The incidence of supraventricular tachyarrhythmias in this group of 291 subjects was identical to that of the original 418 patients at 29% (n = 86). The preoperative medications were studied in 152 patients: 66 were taking a /3 blocker that was discontinued the day of surgery and not reinstituted after surgery unless for the control of supraventricular tachyarrhythmiss. Although the incidence of sustained supraventricular tachyarrhythmias was greater than that in other groups at 36% (n = 24), it was not significant. The number of grafts, aortic cross-clamp time, creatine kinase peak, hemoglobin and hematocrit on the third postoperative day were nearly equivalent in both the supraventricular tachyarrhythmia and nonsupraventricular tachyarrhythmia groups (Table II). The history of a preoperative Q-wave myocardial infarction also did not impact the onset of supraventricular tachyarrhythmias. These dysrhythmias were distributed equally among men and women. Age proved to be a statistically significant risk for the development of supraventricular tachyarrhythmias in these patients. The agefor all subjects with a supraventricular tachyarrhythmia was mean f standard deviation 65 f 8 years, whereas the age for the nonsupraventricular tachyarrhythmia group was 61 f 11 years (p
30
20
10
E 2
0
Jan Feb Mar Apr MayJuaeJuly AugScp Ott Nov Dee
FIGURE 1. The number of admissions for acute atrial fibrillation (AF) per month, the value of monthly alcohol sales in millions of Finnish marks (mFmk) and the mean monthly air temperature in degrees of Celsius from January to December
1999.
proposed, but there are scattered data to indicate that exposure to cold may precipitate ventricular dysrhythmias both in health and in disease.5F6 Epidemiologic studies have shown that morbidity and mortality from coronary heart disease manifest seasonal variation with a
Risk Factors for Atrial Grafting
Fibrillation
Lance H. Crosby, RN, MS, W. Bradley Pifalo, and John A. Burkholder, MD
MD,
trial fibrillation (AF) and other supraventricular tachyarrhythmias have been shown to occur in alA most 30% of patients who have undergone coronary artery bypass grafting (CABG).ie3 Causes may include
From the Cardiac Rehabilitation Department, 490 East North Avenue, Suite 102, Pittsburgh, Pennsylvania 1.5212. Manuscript received June 6, 1990; revised manuscript received and accepted July 25,199O.
1520
THE AMERICAN JOURNAL OF CARDIOLOGY VOLUME 66
peak in winter and a trough in summerin cold and temperate zones.3,4This pattern is reminiscent of the one found in the presentstudy, which suggeststhat the basic underlying mechanismsmay be similar. Our investigation has certain limitations that should be consideredin the interpretation of the data. The study was hospital-based and therefore the occurrence of asymptomatic or nonsustainedepisodesof AF could not be assessed.The data should be otherwiserepresentative, however,becauseour hospital is by far the largest referral center in the province of Uusimaa and also becausepatients contacting private doctors or community health centers for acute-onsettachyarrhythmias are, as a rule, sent to the hospital in our area. We could not ascertain whether the size of the population at risk remained constant throughout the study period. It is extremely unlikely, however, that changes in the population size could explain the variation in admissionsfor AF, becausesimilar variation was not found in the number of all emergency admissionsfor medical reasons.In fact, the rate of all medical admissions was lowest in the first third of the year, when the number of admissionsfor AF washighest. The value of alcohol salesin our provincewasthe only indicator available to us of monthly variation in alcohol consumption by the local population. It had a direct and temperature-independent linear relation to the rate of admissionsfor AF. Even though this associationdid not quite reach the conventional limit of statistical significance, and although the value of alcohol sale is not a perfect surrogate for the real volume of ethanol consumed,we think that thesedata are in reasonableharmony with the concept of alcohol as a risk factor for AF.2,4 1. Alpert JS, PetersenP, GodtfredsenJ. Atria1 fibrillation: natural history, complications and management.Ann Reu Med 1988;39:41-52. 2. Koskinen P, Kupari M, LeinonenH, LuomanmSkiK. Alcohol and new-onset atria1fibrillation: a case-controlstudy of a current series,Br Heart J 1987;57:468473. 3. Vuori I. The heart and the cold. Ann ChinRes 1987;19:156-162. 4. Anonymous.Alcohol and atria1 fibrillation (editorial). Lancet 1985;1:1374.
5. DeBacker G, Jacobs DR Jr, Prineas RJ, Crow RS, Kennedy H, Vilandre .I, Blackburn H. Ventricular prematurebeats:screeningand induction tests in normal men. Cardiology 1980;65:23-41. 6. Lader EW, Kronzon I. Ice-water-inducedarrhythmias in a patient with ischemit heart disease.Ann Intern Med 1982;96:614-615.
After Coronary
Artery
Bypass
Kathleen R. Wall, RN, MS,
direct surgical trauma to the atria1 conductive network, postoperative irritative pericarditis, abrupt P-blocker withdrawal or inadequateatria1protection during cardiopulmonary bypass.4Risk factor profiles for the development of AF after CABG have been compiled without a consistentpattern emerging.5,6The purposeof this study was to evaluate possiblecontributing risk factors for the developmentof AF in a large cohort of patients immediately after CABG.
TABLE
II Operative Characteristics Groups Nonsupraventricular Tachyarrhythmia (n = 205)
I I I
Prospective analysis of consecutive patients immediately after elective CABG were studied. Patients undergoing concomitant cardiac procedures such as left ventricular aneurysm resection, valve repair or replacement, septal defect repair, and so forth, were excluded before the study. Patients with preexisting valvular heart disease or congestive heart failure also were excluded. The anesthetic and surgical techniques were similar for all patients. Patients who experienced an episode of sustained supraventricular tachyarrhythmias postoperatively were grouped for study. Sustained supraventricular tachyarrhythmias were defined as episodes lasting 130 seconds; however, most were persistent, necessitating antiarrhythmic therapy. All patients were maintained on a heart rhythm monitor with arrhythmia detection capabilitiesfor X5postoperative days. The usual hospitalization period was 7 to 9 days. Patients who had postoperative complications such asperioperative Q-wave myocardial infarction, thoracic reexploration and clinical pericarditis were identiBed and analyzed separately. Clinical pericarditis was diagnosed by an audible pericardial friction rub after the removal of all chest tubes, associated symptomatology and treatment with anti-inflammatory agents. Patients with a prior history of atria1 dysrhythmias but normal sinus rhythm at the time of surgery or previous coronary revascularization were also evaluated separately. The remaining population was divided into the supraventricular and nonsupraventricular tachyarrhythmia groups. Factors analyzed to detect differences between groups were (I) preoperative characteristics: age, gender, history of myocardial infarction; and (2) operative characteristics: number of grafts, aortic cross-clamp time, creatine kinase peak, hemoglobin and hematocrit on the third postoperative day and complications during and after surgery. The study data were analyzed with descriptive statistics including mean f standard deviation, andfrequency distributions. Student’s t and chi-square statistics were used to test the statistical significance of group differences. The hospital course of 418 consecutive patients admittedfor elective CABG were followed. Sustainedpostoperative supraventricular tachyarrhythmias occurred in 122patients (29%). Of these, AFoccurred in 85% (n = 104), followed by undefined in 9% (n = I I) and atria1 flutter in 6% (n = 7). Reviewing this group for incidence ofsupraventricular tachyarrhythmias and the following conditions-previous CABG, history of preoperative AF, clinical pericarditis and perioperative myocardial
Creatine kinase
*standard deviation. TThird postoperative NS = not significant.
Supraventricular Tachyarrhythmia (n = 86)
p Value
41(13)9
40(16)
NS
10(l)
9 (2)
NS
29 (3)
27 (5)
NS
763 (607)
877 (824)
NS
2.5 (1)
2.5 (1)
NS
day.
infarction-we found that there were no statistical differences between or among conditions (Table I). After controlling for these conditions, 291 subjects remained. The incidence of supraventricular tachyarrhythmias in this group of 291 subjects was identical to that of the original 418 patients at 29% (n = 86). The preoperative medications were studied in 152 patients: 66 were taking a /3 blocker that was discontinued the day of surgery and not reinstituted after surgery unless for the control of supraventricular tachyarrhythmiss. Although the incidence of sustained supraventricular tachyarrhythmias was greater than that in other groups at 36% (n = 24), it was not significant. The number of grafts, aortic cross-clamp time, creatine kinase peak, hemoglobin and hematocrit on the third postoperative day were nearly equivalent in both the supraventricular tachyarrhythmia and nonsupraventricular tachyarrhythmia groups (Table II). The history of a preoperative Q-wave myocardial infarction also did not impact the onset of supraventricular tachyarrhythmias. These dysrhythmias were distributed equally among men and women. Age proved to be a statistically significant risk for the development of supraventricular tachyarrhythmias in these patients. The agefor all subjects with a supraventricular tachyarrhythmia was mean f standard deviation 65 f 8 years, whereas the age for the nonsupraventricular tachyarrhythmia group was 61 f 11 years (p
