FREQUENCY AND CLINICAL OUTCOME IN CONDUCTION DEFECTS IN ACUTE MYOCARDIAL INFARCTION

Authors

  • Muhammad Asif Bhalli
  • Muhammad Qaiser Khan
  • Naseer Ahmed Samore
  • Sobia Mehreen

Abstract

Background: Conduction defects complicating acute myocardial infarction (MI) are frequent andassociated with increased mortality and complications. Common conduction defects after acute MIare atrioventricular nodal blocks (1st, 2nd and 3rd degree) and intraventricular conduction defects(right or left bundle branch blocks and hemiblocks). In myocardial infarction occlusion ofcoronary arteries at different levels affects the conduction system of heart leading to various typesof blocks. Conduction defects usually reflect extensive damage to the myocardium. Methods: Inthis descriptive case series with non-probability purposive sampling, 345 cases of acute STelevation myocardial Infarction were studied at Armed Forces Institute of Cardiology/NationalInstitute of Heart Disease, Rawalpindi from May 2007 to May 2008. ECG was continuouslyobserved in CCU and daily ECGs were done. Conduction defects whether transient or persistentwere recorded in pre-designed proforma in addition to other clinical features and associatedcomplications during hospital stay. Results: Out of 345 patients, 251 (72.8%) patients receivedthrombolytic therapy and 61 (17.6%) developed various types of conduction defects (Group A)and 284 had no significant conduction defects (Group B). Isolated complete atrioventricular block(AVB) at the node level occurred in 28 patients (8.1%) mainly in inferior MI. Bundle branchesBlocks occurred in 32 (9.2%) patients mostly in Anterior MI. One patient (0.6%) had completeheart block at bundle branch level. All patients with complete atrioventricular block reverted tosinus rhythm except one who required permanent pacemaker. Mortality rate and clinicalcomplications were higher in group A as compared to group B. Conclusion: Conduction defectsare common even in this thrombolytic era. Patients with conduction defects are at high risk ofinhospital complications and mortality. They need close monitoring and optimum clinical care toreduce mortality and morbidity.Keywords: Conduction defects, Acute myocardial infarction, Bundle branch blocks

References

Dubois, C, Picrard LA, Smeets JP, Foidart C, Legrand V,

Kulbertus HE. Short & long term prognostic importance of

complete bundle branch block complicating acute myocardial

infarction. Clin Cardiol 1988;11:292–6.

Klein RC, Vera Z, Mason DT. Intraventricular conduction

defects in acute myocardial infarction: Incidence, prognosis,

and therapy. Am Heart J 1984;108:1007–1.

Godman MJ, Lasers BW, Julian DG. Complete bundle

branch block complicating acute myocardial infarction. N

Engl J Med 1970;282:237–40.

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;94:2424–8.

Matetzky S, Novikov M, Gruberg L, Freimark D, Feinberg

M, Elian D, et al. The significance of persistent ST elevation

versus early resolution of ST segment elevation after primary

PTCA. J Am Coll Cardiol 1999;34:1932-8.

Gann D, Balachandran PK, El-Sherif N, Samet P. Prognostic

significance of chronic versus acute bundle branch block in

acute myocardial infarction. Chest 1975;67:298–303.

James TN, Burch GE. Blood supply of the human

intraventricular septum. Circulation 1958;17:391– 6.

Hindman MC, Wagner GS, JaRo M, Atkins JM, Scheiman

MM, DeSanctis RW et al. The clinical significance of bundle

branch block complicating acute myocardial infarction. II.

Indications for temporary and permanent pacemaker

insertion. Circulation 1978;58:689–99.

Scheinman M, Brenman B. Clinical and anatomic

implications of intraventricular conduction block in acute

myocardial infarction. Circulation 1972;46:753–60.

Hindman MC, Wagner GS, JaRo M, Atkins JM, Scheiman

MM, DeSanctis RW et al,. The clinical significance of

bundle branch block complicating acute myocardial

infarction, 1: clinical characteristics, hospital mortality, and

one-year follow-up. Circulation. 1978;58:679–88.

Thygesen K, Alpert JS, White HD. Universal definition of

Myocardial Infarction.J A Coll Cardiol 2007;50:2173–95.

Sgarbossa EB, Pinski SL, Barbagelata A, Underwood DA,

Gates KB, Topol EJ et al, for the GUSTO-1 (Global

Utilization of Streptokinase and Tissue Plasminogen

Activator for Occluded Coronary Arteries) Investigators.

Electrocardiographic diagnosis of evolving acute myocardial

infarction in the presence of left bundle-branch block. N Engl

J Med 1996;334:481–7.

Willems JL, Robles de Medina EO, Bernard R, Coumel P,

Fisch C, Krikler D, et al. Criteria for intraventricular

conduction disturbances and pre-excitation. World Health

Organizational/International Society and Federation for

Cardiology Task Force Ad Hoc. J Am Coll Cardiol

;5:1261–1275.

Rosenbaum MB. The hemiblock, diagnostic criteria and

clinical significance. Mod Concepts Cardiovasc Dis

;39:141–6.

Clemmenson P , Bates ER, Callif RM , Hlatky MA, Aronson

L, George BS, Lee KL et al. Complete atrioventricular block

complicating inferior wall acute myocardial infarction treated

with reperfusion therapy. Am J Cardiol. 1991;64:224–30

Kostuk WJ, Beanlands DS. Complete heart block associated

with acute myocardial infarction. Am J Cardial 1970;26:380–4.

Jones ME, Terry G, Kenmure AC. Frequency and

significance of conduction defects in acute myocardial

infarction. Am Heart J 1977;94:163–7.

Woo KS. Conduction defects in acute myocardial infarction

in the Chinese in Hong Kong. Int J Cardiol 1990;26:325–34.

Archbold RA, Sayer JW, Ray S, Wilkinson P, Ranjadayalan

K, Timmis AD. Frequency and prognostic implications of

conduction defects in acute myocardial infarction since the

introduction of thrombolytic therapy. Eur Heart J

;19:893–8.

Meine TJ, Al-Khatib SM, Alexander JH, Granger CB, White

HD, Kilaru R et al. Incidence, predictors, and outcomes of

high-degree atrioventricular block complicating acute

J Ayub Med Coll Abbottabad 2009;21(3)

http://www.ayubmed.edu.pk/JAMC/PAST/21-3/Bhalli.pdf 37

myocardial infarction treated with thrombolytic therapy. Am

Heart J 2005;149:670–4.

Bilal HB, Sultan J, Hassan K, Ovais K, Majeed I. Heart

blocks as predictors of Mortality in Acute Myocardial

Infarction . J Rawal Med Coll 1999;3(1–2):13–6.

Majumder AA, Malik A, Zafar A. Conduction disturbances

in acute myocardial infarction: Incidence, site-wise

relationship and the influence on in-hospital prognosis.

Bangladesh Med Res Counc Bull.1996;22:74–80.

Escosteguy CC, Carvalho Mde A, Medronho Rde A, Abreu

LM, Monteiro Filho MY. Bundle branch and

atrioventricular block as complications of acute myocardial

infarction in the thrombolytic era. Arq Bras Cardiol

;76:291–6.

Thompson PL, Fletcher EE, Katavatis V. Enzymatic indices

of myocardial necrosis: influence on short- and long-term

prognosis after myocardial infarction. Circulation

;59:113–19.

Opolski G, Kraska T, Ostrzycki A, Zieliński T, Korewicki J.

The effect of infarct size on atrioventricular and

intraventricular conduction disturbances in acute myocardial

infarction. Int J Cardiol.1986;10:141–7.

Nicod P, Gilpin E, Dittrich H, Polikar R, Henning H, Ross J.

Long-term outcome in patients with inferior myocardial

infarction and complete atrioventricular block. J Am Coll

Cardiol 1988;12:589–94.

Coll JJ, Weinberg SL. The incidence and mortality of

intraventricular conduction defects in acute myocardial

infarction. Am J Cardiol 1972;29:344–50.

Published

2009-09-01