World Journal of Cardiovascular Diseases, 2012, 2, 90-94 WJCD http://dx.doi.org/10.4236/wjcd.2012.22014 Published Online April 2012 (http://www.SciRP.org/journal/wjcd/ ) Left bundle branch block and myocardial infarction, a diagnosis not always easy: Our experience and review of literature Angela Sansone, Francesca Bonura, Fabiana Castellano, Rosanna Iacona, Dario Mancuso, Giuseppina Novo, Pasquale Assennato, Salvatore Novo Department of Internal Medicine, Cardiovascular and Nephro-Urological Disease, Unit of Cardiology, University of Studies “P. Gi- accone” Palermo, Palermo, Italy Email: angela.sansone84@yahoo.it Received 11 January 2012; revised 8 March 2012; accepted 18 March 2012 ABSTRACT The occurrence of left bundle branch block (LBBB) is quite common in clinical practice. The changes in cardiac repolarization, caused by this disorder of electric conduction, may mask the presence of an acute myocardial infarction (AMI), delaying the di- agnostic-therapeutic iter, with an important impact on prognosis. We describe the case of a woman of 59 years with LBBB, came to our observation for a con- strictive chest pain associated with dyspnea. The di- agnostic workup for suspected acute coronary syn- drome (ACS), initially conducted only on the analysis of the electrocardiogram (negative TnI at entry), showed the presence of coronary arteries free of steno- sis. However, the diagnostic confirmation of AMI was completed after the rise of cardiac markers and the electrocardiographic changes. This case confirm the difficulty about the diagnosis of AMI in patients with LBBB and stresses, however, as the use of some crite- ria proposed in the literature [1-3] can guide to its identification, directing patient to an appropriate treatment. Keywords: Left Bundle Branch Block (LBBB); Myocardial Infarction; Electrocardiogram 1. INTRODUCTION The occurrence of a right bundle branch block or a left one, is quite common in routine electrocardiograms (ECGs). In particular, the LBBB is often evident in patients with cardiac injury and/or systemic hypertension. The changes in cardiac repolarization in this disorder of electric con- duction, may also mask the classical electrocardiographic changes of -ST segment in patients with AMI. For years, therefore, several authors have focused their attention on the management of patients with suspected ACS and LBBB on ECG [4-6], in order to identify electrocardio- graphic criteria which could allow the diagnosis of AMI fastest, optimizing at the same time, the results of reper- fusion therapy [7,8]. 2. CASE REPORT Woman of 59 years, hypertensive for about twenty years, smoker, with a positive family history for cardiovascular disease (father died for ACS). Comes to our attention in September 2008 for constrictive chest pain of high inten- sity associated with dyspnea. OE: 3/6 L rough systolic murmur on aortic outbreak, abolition of the second tone, VM harsh. BP: 130/70 mmHg. ECG: SR at frequency of 75 bpm, LBBB (Figure 1). The patient also reports home therapy with: telmisar- tan 80 mg, amlodipine 10 mg, cardioaspirin, omeprazole. Be reported to the blood tests performed in the E. R.: glycaemia 135 mg/dl, neutrophilic leukocytosis (WBC 10.7 × 10 3 μL, NEUT 8.7 × 10 3 μL), LDH 458UI/L, CPK 59 UI/L, TnI 0.017 ng/ml. Given the severity and the persistence of chest pain and the electrocardiographic finding of LBBB, at the time to interpret for the presence of signs that could suggest an AMI in progress, was ad- ministered i.v therapy (ASA, heparin 4000UI, omepra- zole and antibiotic prophylaxis) and moved the patient to Hemodynamic Unit to perform coronary angiography in emergency, that showed the absence of angiographically significant stenosis. The seriated blood test performed during hospitaliza- tion, showed progressive increase in cardiac markers (peak value: LDH 611 UI/L, CPK 317 UI/L, TnI 9.02 ng/ml). Also be noted, sequential electrocardiographic changes (maximum elevation of the J point in V3: 5 mm, V4: 4 mm, V5: 3 mm.) regressed on the second day of ospitalization (Figures 2 and 3). During hospitalization, h OPEN ACCESS