Etiological Distribution of Chronic and Transient Atrial
Fibrillation in Patients at Cantonal Hospital Zenica
Enes Abdović10 yrs Prospective Study,
2940pts from June 2000 to May 2010
5 th Congress of Cardiologists and Angiologistsof Bosnia and Herzegovina
Background
• Atrial fibrillation (AF) is the most prevalent sustained cardiac arrhythmia in developed countries.
• It is a disease of the elderly and it is common in patients (pts) with organic heart disease.
• Hypertension, diabetes mellitus, heart failure and valvular heart disease are predisposing factors to AF.
Aim
• To evaluate relationship of different types of AF (transitory/chronic) with underlying heart disease and demographic characteristics of pts as well
Godtfresen J. Atrial fibrillation: course and prognosis. A follow-up study of 1212 cases. In: Kulbertus HE, Olsson
SB, Schlepper M, eds. Atrial Fibrillation. Mölndal,
Sweden: AB Hässle; 1982:134–145.
• Godtfredsen, retrospectively analyzed the charts of 1212 patients with AF hospitalized in Slagelse, Denmark, during the years 1940 to 1967.
• Chronic AF cases represented 65% of his patients.
The ALFA Study Samuel Lévy et al. Circulation 1999
• The relative prevalences of paroxysmal, chronic, and recent onset AF were 22.1%, 51.4%, and 26.4%, respectively.
• Underlying heart disease was present in 534 patients (70.6%). An absence of underlying heart disease referred to as lone AF was observed in 29.4% of the total patient population despite the wide use of echocardiography.
• Hypertension was the most common underlying condition (39.4%), and hypertensive heart disease was found in 21.4% of the total patient population.
• Of interest is the fact that the incidence of coronary artery disease (16.6%) and myocardial diseases (15.3%) have reached or exceeded the incidence of valvular heart disease in the total cohort (15.2%).
The ALFA Study, 756 pts Samuel Lévy et al. Circulation 1999
Median age 68.6 yrs (19-95)
Male gender 57,7% (436)
Chronic AF 51,4% (389)
Hypertension 39,4% (298)
Diabetes mellitus 10.7% (81)
Thyroid gland diseases
3,1% (24)
Lone AF 29,4% (221)
• Am Heart J 2008;155:197-9
• The development of atrial fibrillation (AF) is a relatively common complication of acute myocardial infarction (AMI) present in ~10% to 15% of AMIs and generally thought to be a marker of adverse prognosis.
“Non pathologic AF”Taggar JS and Lip GYH “Risk Predictors for Atrial Fibrillation” Ed. Europace 2008
• It is estimated that in ~2 – 10% (and possibly as much as 30%) of people presenting with AF there is no identifiable aetiology and this subset of patients is often to reffered as “Lone AF(LAF)”
• LAF is more likely among younger populations. In one study, the mean age at diagnosis of LAF was 46.8 years.
Etiological distribution of pts with AF
39%
25%
15% 12% 3%
8%
0%
5%
10%
15%
20%
25%
30%
35%
40%
45%
HHD DCM CHD VHD Lone Other
Results
Median age 72 years (16-96)
Male gender 48,7% (1426)
Chronic AF 69,9% (2045)
Hypertension 71,1% (2089)
Diabetes mellitus 17.2% (503)
Thyroid gland diseases
6,1% (197)
IV block 29,1% (853)
Age Distribution of pts with AF
Sex and Age Distribution of pts with AF
0
50
100
150
200
250
16-20 21-25 26-30 31-35 36-40 41-45 46-50 51-55 56-60 61-65 66-70 71-75 76-80 81-85 86-90 91-95 96-100
Males
Females
Median age (IQ range) of pts with AF The median age was 72 years,
ranged between 16 and 96 years
Sex
• Female’s predominance in:• HA, VHD, DM,
• Male’s predominance in:• Lone FA, DCM
Transitory vs. Chronic AF
Transitory vs. Chronic AF
Transitory AF
Chronic AF
FemalesOR=1.28 95% CI=1.00-
1.64Sex
Males
Younger ptsOR=1.04 95% CI=1.02-
1.05Age
Older pts
LoneAFOR=3.85 95% CI=1.64-
9.04
Concomitant/
Underlying Disease
DCMOR=2.19 95% CI=1.20-4.01
HypertensionOR=1.47 95% CI=1.07-
2.04
VHDOR=4.27 95% CI=2.24-8.15
Chronic-transitory AF ratio distribuated by age of patients
3,40
3,87
1,69 1,78 2,09
2,94
1,50
2,50
3,50
4,50
56-60 61-65 66-70 71-75 76-80 81-85
Intraventricular Block Distribution
20%
36%
25%18%
24%
0%0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
HHD DCM CHD VHD Lone Other
Without IVB
IVB
Distribution of IVB(%)
LBBB
LBBB+LAHB
LBBB+LPHB
LAHB
LPHB
LAHB+RBBB
LPHB+RBBB
RBBB
20
10
40
1
5
10
410
Summary
Frequency Age Sex Diabetes IV block
HHDthe most common (39%)
DCMthe oldest (71±9 yrs)
males(63%)
the most common (36%)
CHDhighest(23%)
VHDthe youngest(66±11 yrs)
females(63%)
lowest(4%)
only 18%
Lone only 2.5%mostly in younger males (men 72%, average age 56±13 yrs)
A Proposed Model for the Pathogenesis of AF
Experimental and clinical studies have shown that AF is maintained by multiple reentrant wavelets within the atrial muscle.
It has been estimated that a critical number of wavelets (from 3 to 6) is necessary for perpetuation of AF...
Conclusion(1)• The classical risk factors for developing AF
include HA, diabetes mellitus, valvular disease, ischaemic cardiomyopathy, CHF and thyroid disease.
• HHD was by far the most prevalent associated medical condition.
• Chronic AF was predominant in groups with advanced cardiac remodeling such as DCM and VHD. On the contrary to transient AF, it is a disease of the elderly.
Conclusion(2)
• In order to prevent or postpone the development of AF an optimal treatment of hypertension and diabetes mellitus is necessery