From the Clinical Experimental Research Laboratory (P.E., M.D.) and the Section of Preventive Medicine (P.-O.H., H.E.), Department of Medicine, Sahlgrenska University Hospital/Östra, Göteborg, Sweden.
Correspondence to Peter Eriksson, MD, Department of Medicine, Sahlgrenska University Hospital/Östra, SE-416 85 Göteborg, Sweden.
| Abstract |
|---|
|
|
|---|
Methods and ResultsWe studied a random-sampled population of 855 men who were 50 years old in 1963 and followed them up for 30 years with repeated examinations. Men who developed bundle-branch block were studied with regard to cumulative incidence, relationship with cardiovascular disease/risk factors, and survival. The prevalence of bundle-branch block increases from 1% at age 50 years to 17% at age 80 years, resulting in a cumulative incidence of 18%. No significant relationship with ischemic heart disease or mortality was found. Men who would develop bundle-branch block had a bigger heart volume at age 50 years and developed diabetes mellitus and congestive heart disease during follow-up more often than control subjects.
ConclusionsBundle-branch block correlates strongly to age and is common in elderly men. Our results support the theory that bundle-branch block is a marker of a slowly progressing degenerative disease that also affects the myocardium.
Key Words: bundle-branch block epidemiology population survival
| Introduction |
|---|
|
|
|---|
Whether it is the pathogenesis and morphology of the bundle-branch block itself or the relationship or combination with ischemic heart disease that has an impact on mortality is unclear.
As far as we know, no previous study has recorded 12-lead ECGs in a random sample of 50-year-old men with a 30-year follow-up. The aim of our study was to describe the cumulative incidence of bundle-branch block and its relationship with cardiovascular disease, risk factors, and prognosis.
| Methods |
|---|
|
|
|---|
500 000 inhabitants. All residents in Sweden have a unique
national 10-digit registration number based on their date of birth. The
County Census Bureau is required by law to keep registration numbers,
names, and addresses up to date in an official computerized register.
In 1963, a sample was drawn from the population register consisting of
all men born in 1913 on a day divisible by 3 (ie, day 3, 6, 9, etc, of
each month) and living in the city of Göteborg. These criteria
were fulfilled by 973 men, 855 (88%) of whom agreed to participate in
a health examination. From the baseline examination in 1963, when all
the men were 50 years old, 855 men have been followed up for 30 years
with repeated examinations (in 1967, 1973, 1980, 1988, and 1993). Those
who did not participate in the examinations were asked to fill out
questionnaires or participate in telephone interviews. Information
about hospitalization, medication, and morbidity since the previous
examination was obtained at each examination. Death certificates,
autopsy reports, and medical records were studied for those who
died. The participants and nonparticipants have previously been
described in detail (References 2020 to 23). Systematic 12-lead ECG
recordings were made in 1963, 1980, 1988, and 1993 and form the
basis of the present study (Table 1
|
ECG
Standard 12-lead ECGs were recorded with the patients at
rest in the supine position. Paper speed was 50 mm/s, and
calibration was 1 mV:10 mm. All 12-lead ECGs were read by one of
the authors (P.E.), who was blinded to all data, and were classified as
to whether bundle-branch block was present or not.
Left bundle-branch block was defined as (1) QRS duration
120 ms, (2)
PQ interval >120 ms, (3) predominantly upright complexes with slurred
R waves in leads I, V5, and
V6, and (4) QS or rS pattern in
V1.
Right bundle-branch block was defined as (1) QRS duration
120 ms, (2)
PQ interval >120 ms, (3) rSR' in lead V1 or
V2, and (4) S waves in lead I and either lead
V5 or V6. They were further
classified according to the QRS axis in the presence of right
bundle-branch block, in which an axis <-30° or >+90° indicated a
possibility of a bifascicular block (concomitant left anterior
hemiblock or left posterior hemiblock,
respectively).24
If atrial fibrillation was present, the ECG was still included as bundle-branch block even if the criterion of PQ interval >120 ms could not be fulfilled. Left ventricular hypertrophy was defined as Sokolow-Lyon criterion >3.5 mV25 and was measured only in men with QRS complex <120 ms before they developed bundle-branch block.
Baseline Examinations in 1963
Participants were examined in the morning after an overnight
fast. Body weight was measured with a balance scale to the nearest 0.1
kg with the men wearing light indoor clothing. Height was measured to
the nearest centimeter. Body mass index was calculated as weight (kg)
divided by the square of height (m2).
Blood pressure was recorded in the right arm, with the participant seated after a 5-minute interview. A mercury sphygmomanometer with a cuff size of 12x23 cm was used. All blood pressures were measured by the same observer to the nearest 2 mm Hg.
Chest radiographs were taken during inspiration in the frontal, left lateral, and 2 oblique projections. Radiographs were interpreted by 2 experienced radiologists who had no other information about the participants. Absolute heart volume (mL) was measured on the radiograph according to Jonsell.26
Blood samples were drawn from an antebrachial vein for determination of serum cholesterol, serum triglycerides, and blood glucose. Information on smoking habits was obtained by questionnaire.
Follow-Up
From the baseline examination in 1963, 855 men were followed up
for a mean of 30.5±0.5 (±range) years, with repeated examinations in
1967, 1973, 1980, 1988, and 1993.
Of the men still alive in 1993, 232 attended the examination. Of the men who did not participate in 1993, 67 were interviewed by telephone, 29 answered a questionnaire, and medical records were studied for another 32. Six of the men had left the country and were unavailable to follow-up. Another 7 men were unavailable for end-point registration because they had moved out of the area and their medical records could not be found. Among these 7 men, 1 had right bundle-branch block and died in 1995. He has been included in the calculation of the survival data. Thus, the clinical follow-up rate during the 30-year follow-up period was 98%.
Morbidity data for coronary heart disease and stroke were obtained by interview, from death certificates, from the Myocardial Infarction Register,27 and from the Stroke Register28 covering the city of Göteborg. The criteria for stroke were hospital admission with the diagnosis of stroke or a fresh cerebral thrombosis or hemorrhage at postmortem examination.
The criteria for ischemic heart disease during follow-up were
myocardial infarction defined by the Swedish Society of
Cardiology, postmortem findings of fresh
coronary heart disease, or hospitalization due to angina
pectoris/unstable angina pectoris and suspected acute myocardial
infarction. The end point congestive heart failure was defined as
hospitalization for heart failure or outpatient treatment for heart
failure for at least 3 months. Diabetes mellitus was defined as known
diabetes mellitus under treatment or fasting blood glucose
6.7
mmol/L.
Statistics
The study group consisting of bundle-branch block was compared
with the rest of the population with available ECGs (Table 1
).
Nonparametric tests were used. For difference between
groups, the Wilcoxon rank sum test was used for continuous
variables. Differences in proportions were analyzed with
the
2 test. A life-table method according to
Kaplan-Meier29 was used to calculate the survival
curves and the cumulative incidence for bundle-branch block. The
cumulative incidence was based on those still alive and available to
follow up with regard to ECGs. Men with bundle-branch block were not
considered at risk the next year.
| Results |
|---|
|
|
|---|
|
The prevalence of bundle-branch block, both right and left, increased
with age. Right bundle-branch blocks were more common than left
bundle-branch blocks (Table 3
). At age 75
years, the prevalence of right bundle-branch block was >4 times that
of left bundle-branch block. The cumulative incidence rate for all
bundle-branch blocks at age 80 years was 18.1% (left bundle-branch
block, 6.5% and right bundle-branch block, 12.9%) (Figure 1
).
|
|
All patients who were alive and had an ECG taken at the age of 67, 75,
and 80 years were analyzed separately for differences in
coronary risk factors at age 50 years as well as being given a
diagnosis of myocardial infarction, ischemic heart disease,
congestive heart failure, or diabetes mellitus during follow-up (Tables 4
, 5
, and 6
).
|
|
|
In survivors, at age 67, 75, and 80 years, there were no significant
differences in risk factor profile at age 50 between those who
subsequently developed bundle-branch block and those who did not, and
there was no significant difference in having myocardial infarction or
a diagnosis of ischemic heart disease during follow-up. The
heart volume at age 50 years was consistently larger among
those who developed bundle-branch block (the majority had not developed
bundle-branch block at the time of their radiographs in 1963) compared
with control subjects. A diagnosis of congestive heart failure during
follow-up was significantly more common among those with bundle-branch
block. The biggest difference was found in survivors at age 67 years,
among whom 36% of those with bundle-branch block developed congestive
heart failure, compared with 14% of the control subjects (Table 4
).
Diabetes mellitus was also more common among men who developed
bundle-branch block.
Survival and Mortality
Survival curves for men with and without bundle-branch block were
calculated separately at age 50, 67, and 75 years to avoid survival
bias (Figures 2
, 3
, and 4
,
respectively). On all 3 curves, men with bundle-branch block showed a
nonsignificant trend toward a higher mortality. Among men who died
without being known to have bundle-branch block, 262 of 446 deaths
(59%) were diagnosed as being cardiovascular, compared
with 23 of 35 (66%) in patients with bundle-branch block
(P=NS). Among those who died of
cardiovascular causes without being known to have
bundle-branch block, 73 of 262 (28%) had a prior diagnosis of chronic
congestive heart failure, compared with 14 of 23 (61%) in patients
with bundle-branch block (P<0.01).
|
|
|
| Discussion |
|---|
|
|
|---|
52
years old.12 The Tecumseh study showed the
prevalence of bundle-branch block to be 2.4% in men >50 years
old.30 In the study by Kreger et
al,31 complete
intraventricular block, defined as QRS
0.12
second, was strongly dependent on age, with a prevalence of 11% in men
in the 8th and 9th decades, and was twice as common in men as in women.
Our results, as shown in Table 3
Relationship With Coronary Heart Disease
In the Framingham Heart Study,13
univariate analysis showed an increased risk of
subsequent development of coronary heart disease or congestive
heart failure in patients who developed bundle-branch block. When
adjusted for age, this difference was not significant. Froelicher et
al,32 using coronary angiography,
examined 75 asymptomatic male aircrew members with
bundle-branch block and found significant stenoses in 16 (22%)
of the men but no causal correlation to the length of the left main
coronary artery and numbers of septal perforators in left
bundle-branch block, as stated earlier in a study by
Herbert.33 Patients with chest pain and right
bundle-branch block were angiographically studied by Haft et
al,34 and no difference in severity or extension
in coronary artery disease was seen compared with control
subjects. From the Coronary Artery Surgery
Study,16 with >15 000 patients with chronic
coronary artery disease, 522 patients with bundle-branch block
were identified. No particular location of coronary
stenosis or left ventricular wall motion
abnormalities predominated, indicating that the bundle-branch block was
the result of infarction of the proximal conduction system.
In our study, with regard to risk factors for coronary heart
disease at age 50 years, there was no difference between those who
developed bundle-branch block and those who did not, except for
diabetes mellitus, which was more common in men with bundle-branch
block. The risk of having or developing ischemic heart
disease/myocardial infarction in the future was not higher in the
bundle-branch block population. In our population, coronary
heart disease did not seem to play any major role in the development of
bundle-branch block; instead, our study supports the theory that
bundle-branch block is a progressive degenerative disease that affects
not only the conduction system but also the myocardium
itself, as shown by a larger heart volume at age 50 years in those who
developed bundle-branch block at follow-up and a significantly higher
incidence of the diagnosis of congestive heart failure during follow-up
(Tables 4 to 6![]()
![]()
).
Mortality
Considerable information in the literature indicates that patients
with bundle-branch block, either right or left, may have normal
longevity.9 10 11 35 36 37 In the Framingham Study,
an increased mortality from cardiovascular disease was
seen in people with bundle-branch block. However, total mortality was
not described.13
Despite the high prevalence of coronary heart disease in patients with bundle-branch block, the onset of chronic bundle-branch block is only rarely accompanied by clinically recognized myocardial infarction. More often, bundle-branch block is discovered as an incidental accompaniment to chronic coronary artery disease. In studies of myocardial infarction/ischemic heart disease, bundle-branch block has been shown to be a strong predictor of high mortality at follow-up.16 17 19 38 39 40 Bundle-branch block has been reported to be present in 13% of patients with acute myocardial infarction.38 41 42 43 In our study, no increased mortality was seen in men with bundle-branch block at follow-up and no difference in the incidence of ischemic heart disease or death due to cardiovascular disease.
Coronary heart disease does not seem to play any major role in the pathogenesis of bundle-branch block. Rather, in our own study and those of others, bundle-branch block gives the impression of being a marker of a slowly progressing degenerative disease affecting not only the conduction system but also the myocardium.44 45 46 A slow increase in cumulative mortality over time would then be expected but would be detected only in large populations followed up for a long period of time.
The marked increase in mortality in patients with bundle-branch block is seen only in combination with ischemic heart disease. In bundle-branch block, the depolarization phase is by definition prolonged. Furthermore, the prolongation of the vulnerable repolarization phase in combination with an increased number of premature ventricular beats (secondary to ischemic heart disease) would expose the patient to an increased risk of sudden ventricular tachyarrhythmias.
This theory is supported by electrophysiological studies of patients with bifascicular block, in whom sustained monomorphic ventricular tachycardia was induced exclusively in patients with a previous myocardial infarction.47 Furthermore, McAnulty et al3 followed up 554 patients with bundle-branch block and noticed an increased risk of sudden death due not to bradyarrhythmias but rather to tachyarrhythmias and myocardial infarction.
Another explanation of the high mortality from acute myocardial infarction could be a degenerative cardiomyopathy less able to compensate for a sudden loss of functional myocardium during the course of an acute myocardial infarction.
Limitations of the Study
We looked at ECG recordings on only 4 occasions during a
follow-up period of 30 years. In men who died who were not regarded as
having bundle-branch block, we do not know whether they would have
developed bundle-branch block before death. If that number is
substantial, our results underestimate the cumulative incidence and
mortality of bundle-branch block. Because both bundle-branch block and
ischemic heart disease differ in a number of ways between
sexes, our results cannot be extrapolated to women.
Conclusions
In a prospective population sample of men at age 50 years who were
then followed up for 30 years, bundle-branch block was found to be
common in elderly men and to increase with age. No correlation to risk
factors for coronary heart disease at age 50 years, incidence
of myocardial infarction during follow-up, or
cardiovascular deaths was found. The results support
the theory that bundle-branch block is a marker of a progressive
degenerative disease that also affects the myocardium.
| Acknowledgments |
|---|
| References |
|---|
|
|
|---|
2. McAnulty HJ, Rahimtoola HS, Murphy SE, Kauffman S, Ritzmann WL, Kanarek P, DeMots H. A prospective study of sudden death in "high-risk" bundle-branch block. N Engl J Med. 1978;299:209215.[Abstract]
3. McAnulty HJ, Rahimtoola HS, Murphy E, DeMots H, Ritzmann L, Kanarek EP, Kauffman S. Natural history of "high-risk" bundle-branch block. N Engl J Med. 1982;307:137143.[Abstract]
4. Johnson PR, Messer LA, Shreenivas, White DP. Prognosis in bundle-branch block, II: factors influencing the survival period in left bundle-branch block. Am Heart J. 1951;41:225238.[Medline] [Order article via Infotrieve]
5. Messer LA, Johnson PR, Shreenivas, White DP. Prognosis in bundle-branch block, III: a comparison of right and left bundle-branch block with a note on the relative incidence of each. Am Heart J. 1951;41:239245.[Medline] [Order article via Infotrieve]
6.
Scanlon JP, Pryor R, Blount SG. Right bundle-branch
block associated with left superior or inferior
intraventricular block. Circulation. 1970;42:11231133.
7. Shreenivas, Messer LA, Johnson PR, White DP. Prognosis in bundle-branch block, I: factors influencing the survival period in right bundle-branch block. Am Heart J. 1950;40:891902.[Medline] [Order article via Infotrieve]
8. Smith S, Hayes LW. The prognosis of complete left bundle-branch block. Am Heart J. 1965;70:157159.[Medline] [Order article via Infotrieve]
9.
Rotman M, Triebwasser HJ. A clinical and follow-up
study of right and left bundle-branch block. Circulation. 1975;51:477484.
10. Fahy JG, Pinski LS, Miller PD, McCabe N, Pye C, Walsh JM, Robinson K. Natural history of isolated bundle-branch block. Am J Cardiol. 1996;77:11851190.[Medline] [Order article via Infotrieve]
11.
Rodstein M, Gubner R, Mills PJ, Lovell FJ, Ungerleider
E. A mortality study in bundle-branch block. Arch Intern
Med. 1951;87:663668.
12.
Edmands RE. An epidemiological assessment of
bundle-branch block. Circulation. 1966;34:10811087.
13. Schneider FJ, Thomas EH, Sorlie P, Kreger EB, McNamara MP, Kannel BW. Comparative features of newly acquired left and right bundle-branch block. Am J Cardiol. 1981;47:931940.[Medline] [Order article via Infotrieve]
14. Hardarson T, Arnarson A, Eliasson JG, Palsson K, Eyjolfsson K, Sigfusson N. Left bundle-branch block: prevalence, incidence, follow-up and outcome. Eur Heart J. 1987;8:10751079.
15.
Thrainsdottir I, Hardarson T, Thorgeirsson G,
Sigvaldason G, Sigfusson N. The epidemiology of
right bundle-branch block and its association with
cardiovascular morbidity: the Reykjavik Study.
Eur Heart J. 1993;14:15901596.
16. Freedman R, Alderman E, Sheffield T, Saporito M, Fisher L, Coronary Artery Surgery Study (CASS). Bundle-branch block in patients with chronic coronary artery disease: angiographic correlates and prognostic significance. J Am Coll Cardiol. 1987;10:7380.[Abstract]
17. Col JJ, Weinberg SL. The incidence and mortality of intraventricular conduction defects in acute myocardial infarction. Am J Cardiol. 1972;29:344350.[Medline] [Order article via Infotrieve]
18.
Newby KH, Pisano E, Krucoff MW, Green C, Natale A.
Incidence and clinical relevance of the occurrence of bundle-branch
block in patients treated with thrombolytic therapy.
Circulation. 1996;94:24242428.
19. Fibrinolytic Therapy Trialists' (FTT) Collaborative Group. Indications for fibrinolytic therapy in suspected acute myocardial infarction: collaborative overview of early mortality and major morbidity results from all randomised trials of over 1000 patients. Lancet. 1994;343:311322.[Medline] [Order article via Infotrieve]
20. Tibblin G. A population study of 50-year-old men: an analysis of the non-participant group. Acta Med Scand. 1965;178:453458.[Medline] [Order article via Infotrieve]
21. Tibblin G. High blood pressure in men aged 50. Acta Med Scand. 1967;470:184.
22. Eriksson H, Svärdsudd K, Larsson B, Ohlsson L-O, Welin L, Tibblin G, Wilhelmsson L. Dyspnea in a cross sectional and longitudinal study of middle aged men. The Study of Men Born 1913. Eur Heart J. 1987:8:10151023.
23.
Hansson PO, Wilhelmsen L, Tibblin G, Eriksson H. Deep
vein thrombosis and pulmonary embolism in the general
population. Arch Intern Med. 1997;157:16651670.
24. Schneider JF, Thomas H, Kreger BE, McNamara PM, Sorlie P, Kannel WB. Newly acquired right bundle-branch block: the Framingham Study. Ann Intern Med. 1980;92:3744.
25. Sokolow M, Lyon TP. The ventricular complex in left ventricular hypertrophy as obtained by unipolar precordial and limb leads. Am Heart J. 1949;37:161186.[Medline] [Order article via Infotrieve]
26. Jonsell SA. A method for the determination of the heart size by teleroentgenography. Acta Radiol. 1939;20:325340.
27. Elmfeldt D, Wilhelmson L, Tibblin G, Vedin JA, Wilhelmsson C-E, Bengtsson C. Registration of myocardial infarction in the city of Göteborg, Sweden. J Chronic Dis. 1975;28:173186.[Medline] [Order article via Infotrieve]
28. Harmsen P, Tibblin G. A stroke register in Göteborg, Sweden. Acta Med Scand. 1972;191:463470.[Medline] [Order article via Infotrieve]
29. Kaplan EL, Meier P. Nonparametric estimation from incomplete observations. J Am Stat Assoc. 1958;53:457481.
30.
Ostrander LD, Brandt RL, Kjelsberg MO, Epstein FH.
Electrocardiographic findings among the adult population of a total
natural community, Tecumseh, Michigan. Circulation. 1965;31:888898.
31. Kreger BE, Anderson KM, Kannel WB. Prevalence of intraventricular block in the general population: the Framingham Study. Am Heart J. 1989;117:903910.[Medline] [Order article via Infotrieve]
32. Froelicher VF, Thompson AJ, Wolthuis R, Fuchs R, Balusek R, Longo MR, Triebwasser JH, Lancaster MC. Angiographic findings in asymptomatic aircrewmen with electrocardiographic abnormalities. Am J Cardiol. 1977;39:3238.[Medline] [Order article via Infotrieve]
33. Herbert WH. Left bundle-branch block and coronary artery disease. J Electrocardiol. 1975;8:317324.
34. Haft JI, DeMaio SJ, Bartoszyk OB. Coronary arteriographic findings in symptomatic right bundle-branch block. Am J Cardiol. 1984;53:770773.[Medline] [Order article via Infotrieve]
35. Schreenivas, Messer AL, Johnson RP, White PD. Prognosis in bundle-branch block. Am Heart J. 1950;40:891902.
36. Langley RW, Reed JC, Utz DC. Bundle-branch block: a review of 100 cases. Am Heart J. 1947;33:730.
37. Smith RF, Jackson DH, Harthorne JW, Sanders CA. Acquired bundle-branch block in a healthy population. Am Heart J. 1970;80:746751.[Medline] [Order article via Infotrieve]
38.
Hindman MC, Wagner GS, JaRo M, Atkins JM, Scheinman MM,
DeSanctis RW, Hutter AH Jr, Yeatman L, Rubenfire M, Pujura C, Rubin M,
Morris JJ. The clinical significance of bundle-branch block
complicating acute myocardial infarction, I: clinical characteristics,
hospital mortality, and one-year follow-up. Circulation. 1978;58:679688.
39.
Eriksson P, Andersen K, Swedberg K, Dellborg M.
Vectorcardiographic monitoring of patients with acute myocardial
infarction and chronic bundle-branch block. Eur Heart
J. 1997;18:12881295.
40. Piérard LA, Dubois C, Albert A, Smeets JP, Kulbertus HE. Prediction of mortality after myocardial infarction by simple clinical variables recorded during hospitalization. Clin Cardiol. 1989;12:500504.[Medline] [Order article via Infotrieve]
41. Mullins CB, Atkins JM. Prognosis and management of ventricular conduction blocks in acute myocardial infarction. Mod Concepts Cardiovasc Dis. 1976;45:129133.[Medline] [Order article via Infotrieve]
42. Killip T, Kimball JT. Treatment of myocardial infarction in a coronary care unit: a two year experience with 250 patients. Am J Cardiol. 1967;20:457464.[Medline] [Order article via Infotrieve]
43. Bigger JT, Dresdale RJ, Heissenbuttel RH, Welch FM, Wit AL. Ventricular arrhythmias in ischemic heart disease: mechanism, prevalence, significance and management. Prog Cardiovasc Dis. 1977;19:255300.[Medline] [Order article via Infotrieve]
44. Lenegre J. Etiology and pathology of bilateral bundle-branch block in relation to complete heart block. Prog Cardiovasc Dis. 1964;6:409444.
45.
Davies M, Harris A. Pathological basis of primary heart
block. Br Heart J. 1969;31:219226.
46.
Kuhn H, Breithart G, Knieriem HJ, Köhler E,
Lösse B, Seipel L, Loogen F. Prognosis and possible
presymptomatic manifestations of congestive
cardiomyopathy. Postgrad Med J. 1978;54:451459.
47. Englund A, Bergfeldt L, Rehnqvist N, Åström H, Rosenqvist M. Diagnostic value of programmed ventricular stimulation in patients with bifascicular block: a prospective study of patients with and without syncope. J Am Coll Cardiol. 1995;26:15081515.In a random-sampled population of 855 men 50 years old in 1963 followed up for 30 years, we studied men who developed bundle-branch block with regard to cumulative incidence, relationship with cardiovascular disease/risk factors, and survival. The cumulative incidence for development of bundle-branch block was 18%. No significant relationship with ischemic heart disease or mortality was found. Men who would develop bundle-branch block had a bigger heart volume at age 50 years and developed diabetes mellitus and congestive heart disease during follow-up more often than control subjects. Our results support the theory that bundle-branch block is a marker of a slowly progressing degenerative heart disease.[Abstract]
This article has been cited by other articles:
![]() |
Authors/Task Force Members, P. E. Vardas, A. Auricchio, J.-J. Blanc, J.-C. Daubert, H. Drexler, H. Ector, M. Gasparini, C. Linde, F. B. Morgado, et al. Guidelines for cardiac pacing and cardiac resynchronization therapy: The Task Force for Cardiac Pacing and Cardiac Resynchronization Therapy of the European Society of Cardiology. Developed in Collaboration with the European Heart Rhythm Association Europace, October 1, 2007; 9(10): 959 - 998. [Full Text] [PDF] |
||||
![]() |
Authors/Task Force Members, P. E. Vardas, A. Auricchio, J.-J. Blanc, J.-C. Daubert, H. Drexler, H. Ector, M. Gasparini, C. Linde, F. B. Morgado, et al. Guidelines for cardiac pacing and cardiac resynchronization therapy: The Task Force for Cardiac Pacing and Cardiac Resynchronization Therapy of the European Society of Cardiology. Developed in Collaboration with the European Heart Rhythm Association Eur. Heart J., September 2, 2007; 28(18): 2256 - 2295. [Full Text] [PDF] |
||||
![]() |
F. Zannad, E. Huvelle, K. Dickstein, D. J. van Veldhuisen, C. Stellbrink, L. Kober, S. Cazeau, P. Ritter, A. P. Maggioni, R. Ferrari, et al. Left bundle branch block as a risk factor for progression to heart failure Eur J Heart Fail, January 1, 2007; 9(1): 7 - 14. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Ghostine, C. Caussin, B. Daoud, M. Habis, E. Perrier, D. Pesenti-Rossi, A. Sigal-Cinqualbre, C.-Y. Angel, B. Lancelin, A. Capderou, et al. Non-Invasive Detection of Coronary Artery Disease in Patients With Left Bundle Branch Block Using 64-Slice Computed Tomography J. Am. Coll. Cardiol., November 21, 2006; 48(10): 1929 - 1934. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Dhingra, M. J. Pencina, T. J. Wang, B.-H. Nam, E. J. Benjamin, D. Levy, M. G. Larson, W. B. Kannel, R. B. D'Agostino Sr, and R. S. Vasan Electrocardiographic QRS Duration and the Risk of Congestive Heart Failure: The Framingham Heart Study Hypertension, May 1, 2006; 47(5): 861 - 867. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. M. Marcus, E. Rose, E. M. Viloria, J. Schafer, T. De Marco, L. A. Saxon, E. Foster, and for the VENTAK CHF/CONTAK-CD Biventricular Pacing Septal to Posterior Wall Motion Delay Fails to Predict Reverse Remodeling or Clinical Improvement in Patients Undergoing Cardiac Resynchronization Therapy J. Am. Coll. Cardiol., December 20, 2005; 46(12): 2208 - 2214. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Eriksson, L. Wilhelmsen, and A. Rosengren Bundle-branch block in middle-aged men: risk of complications and death over 28 years: The Primary Prevention Study in Goteborg, Sweden Eur. Heart J., November 1, 2005; 26(21): 2300 - 2306. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Ammann, C. Sticherling, D. Kalusche, J. Eckstein, A. Bernheim, B. Schaer, and S. Osswald An Electrocardiogram-Based Algorithm To Detect Loss of Left Ventricular Capture during Cardiac Resynchronization Therapy Ann Intern Med, June 21, 2005; 142(12_Part_1): 968 - 973. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Padeletti, M. Giaccardi, F. Turreni, N. Musilli, A. Colella, P. Pieragnoli, A. Michelucci, G. Ricciardi, and M. C. Porciani Influence of QRS prolongation on the natural history of CHF Eur. Heart J. Suppl., August 1, 2004; 6(suppl_D): D79 - D82. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. S. Crow, P. J. Hannan, and A. R. Folsom Prognostic Significance of Corrected QT and Corrected JT Interval for Incident Coronary Heart Disease in a General Population Sample Stratified by Presence or Absence of Wide QRS Complex: The ARIC Study With 13 Years of Follow-Up Circulation, October 21, 2003; 108(16): 1985 - 1989. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. V. Pitzalis, M. Iacoviello, R. Romito, F. Massari, B. Rizzon, G. Luzzi, P. Guida, A. Andriani, F. Mastropasqua, and P. Rizzon Cardiac resynchronization therapy tailored by echocardiographic evaluation of ventricular asynchrony J. Am. Coll. Cardiol., November 6, 2002; 40(9): 1615 - 1622. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. A. Saxon and T. De Marco Cardiac resynchronization: a cornerstone in the foundation of device therapy for heart failure J. Am. Coll. Cardiol., December 1, 2001; 38(7): 1971 - 1973. [Full Text] [PDF] |
||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Circulation Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 1998 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |