Testa-Fernández et al. Journal of Medical Case Reports 2011, 5:304 http://www.jmedicalcasereports.com/content/5/1/304 C A S E R E P O R T JOURNAL OF MEDICAL CASE REPORTS Open Access “Giant R wave” electrocardiogram pattern during exercise treadmill test: A case report Ana Testa-Fernández*, Ramón Rios-Vazquez, Juan Sieira-Rodríguez-Moret, Raúl Franco-Gutierrez, Carlos Peña-Gil, Ruth Pérez-Fernández, Victor Puebla-Rojo, Margarita Regueiro-Abel and Carlos Gonzalez-Juanatey Abstract Introduction: The exercise treadmill test is widely used in the evaluation of patients with suspected or known coronary artery disease. The typical ischemic response used to be ST-segment depression. Case presentation: We describe a case of a 51-year-old Caucasian man with an unusual ischemic response during the exercise treadmill test: a “giant R wave” electrocardiogram pattern as a manifestation of hyperacute ischemia that resolved with sublingual nitroglycerin. Coronary catheterization showed a severe stenosis in a proximal dominant circumflex coronary artery. We hypothesize that, in this case, the “giant R wave” pattern was related to severe hyperacute ischemia due to coronary spasm superimposed on the atherosclerotic lesion, which probably caused complete occlusion of the artery. The patient was successfully treated with coronary percutaneous revascularization. Conclusions: This is a dramatic and rare ischemic response during the exercise treadmill test, in which, a rapid administration of nitroglycerin can prevent life-threatening events. Introduction A typical ischemic response during an exercise treadmill test (ETT) is ST-segment depression. ST-segment eleva- tion is present in only about 3.5% of patients who undergo this test [1] and is more specific for indicating the site of the culprit lesion [2,3]. The “giant R wave syndrome” was first described by Prinzmetal et al. [4] in the context of variant angina, and it is characterized by the appearance of a giant R wave, loss of the S wave, and merging of the QRS complex with the ST segment, causing a monophasic QRS-ST complex in leads facing the ischemic territory. This pattern may be rarely observed following coronary artery occlusion in acute myocardial infarction (MI), following variant angina dur- ing an ETT (or spontaneously at rest), and after percu- taneous transluminal coronary angioplasty or experimental coronary artery ligation [5]. We report a case of a patient who developed the giant R wave syn- drome during an ETT. * Correspondence: ana.testa.fernandez@gmail.com Department of Cardiology, Hospital Lucus Augusti, San Cibrao s/n, Lugo E- 27003, Spain Case presentation A 51-year-old Caucasian man with the cardiovascular risk factors of hypertension and smoking was admitted to our hospital because of chest pain and syncope dur- ing exercise. He had experienced intermittent chest pain for one week prior to presentation. Upon admission, his blood pressure was 110/70 mmHg and his pulse rate was 70 beats/minute. His physical examination was unremarkable. His routine biochemistry laboratory para- meters and full blood cell count were normal. A chest radiograph did not show indications of left-sided cardiac failure. A 12-lead electrocardiogram (ECG) obtained without chest pain in the patient showed normal sinus rhythm at 63 beats/minute without Q waves and with a normal QRS width (Figure 1). The echocardiogram showed a normal left ventricular ejection fraction with- out regional motion abnormalities. The patient was referred for exercise testing using a standard Bruce pro- tocol. The test was stopped at minute 10 of the protocol because the patient was experiencing fatigue, had an increasing heart rate of 148 beats/minute (87% of maxi- mal predicted heart rate), had maximal blood pressure of 183/98 mmHg, and had a workload of 12.8 metabolic equivalents without clinical symptoms or ECG © 2011 Testa-Fernández et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.