Background
Wellens syndrome was first described in the early 1980s by de Zwaan, Wellens, and colleagues, who identified a subset of patients with unstable angina who had specific precordial T-wave changes and subsequently developed a large anterior wall myocardial infarction (MI).[1] Wellens syndrome refers to these specific electrocardiographic (ECG) abnormalities in the precordial T-wave segment, which are associated with critical stenosis of the proximal left anterior descending (LAD) coronary artery.
Wellens syndrome is also referred to as LAD coronary T-wave syndrome.[2] Syndrome criteria include the following:
- Characteristic T-wave changes
- History of anginal chest pain
- Normal or minimally elevated cardiac enzyme levels
- ECG without Q waves, without significant ST-segment elevation, and with normal precordial R-wave progression
Recognition of this ECG abnormality is of paramount importance because this syndrome represents a preinfarction stage of coronary artery disease (CAD) that often progresses to a devastating anterior wall MI.
Pathophysiology
Wellens syndrome represents critical stenosis of the LAD artery. The LAD arises from the left coronary artery and travels in the interventricular groove along the anterior portion of the heart to the apex. This groove is situated between the right and left ventricles of the heart. The LAD gives rise to 2 main branches, the diagonals and the septal perforators.[6]
A lesion in the LAD can have severe consequences, as suggested by the common nickname given to this vessel: “widow maker.” The LAD supplies the anterior wall of the heart, including both ventricles, as well as the septum. An occlusion in this vessel can result in serious ventricular dysfunction, thus placing the patient at serious risk for congestive heart failure (CHF) and death.
Etiology
Wellens syndrome is a preinfarction stage of CAD. Thus, the causes of Wellens syndrome are similar to the conditions that cause CAD, including the following:
- Atherosclerotic plaque
- Coronary artery vasospasm (cocaine is one possible cause)
- Increased cardiac demand
- Generalized hypoxia
Risk factors for Wellens syndrome include the following:
- Smoking history
- Diabetes mellitus
- Hypertension
- Increased age
- Hypercholesterolemia
- Hyperlipidemia
- Metabolic syndrome
- Strong family history of heart disease
- Occupational stress
Epidemiology and Prognosis
The characteristic ECG pattern of Wellens syndrome is relatively common in patients who have symptoms consistent with unstable angina. Of patients admitted with unstable angina, this ECG pattern is present in 14-18%.[5, 1]
Wellens syndrome represents critical LAD disease; accordingly, its natural progression leads to anterior wall MI. This progression is so likely that medical management alone is not enough to stop the natural process. Evolution to an anterior wall MI is rapid, with a mean time of 8.5 days from the onset of Wellens syndrome to infarction.[1]
If anterior wall MI occurs, there is the potential for substantial morbidity or mortality. Thus, it is of utmost importance to recognize this pattern early.
de Zwaan C, Bar FW, Wellens HJ. Characteristic electrocardiographic pattern indicating a critical stenosis high in left anterior descending coronary artery in patients admitted because of impending myocardial infarction. Am Heart J. Apr 1982;103(4 Pt 2):730-6. [Medline].
Nisbet BC, Zlupko G. Repeat Wellens' Syndrome: Case Report of Critical Proximal Left Anterior Descending Artery Restenosis. J Emerg Med. Apr 2 2008;[Medline].
Tandy TK, Bottomy DP, Lewis JG. Wellens' syndrome. Ann Emerg Med. Mar 1999;33(3):347-51. [Medline].
Rhinehardt J, Brady WJ, Perron AD, Mattu A. Electrocardiographic manifestations of Wellens' syndrome. Am J Emerg Med. Nov 2002;20(7):638-43. [Medline].
de Zwaan C, Bar FW, Janssen JH, et al. Angiographic and clinical characteristics of patients with unstable angina showing an ECG pattern indicating critical narrowing of the proximal LAD coronary artery. Am Heart J. Mar 1989;117(3):657-65. [Medline].
Moore KL, Dalley AF. Thorax. In: Clinically Oriented Anatomy. 4th ed. Baltimore, Maryland: Lippincott Williams & Wilkins; 1999:135.
Narasimhan S, Robinson GM. Wellens syndrome: a combined variant. J Postgrad Med. Jan-Mar 2004;50(1):73-4. [Medline].
Tatli E, Aktoz M, Buyuklu M, Altun A. Wellens' syndrome: the electrocardiographic finding that is seen as unimportant. Cardiol J. 2009;16(1):73-5. [Medline].
Movahed MR. Wellens' syndrome or inverted U-waves?. Clin Cardiol. Mar 2008;31(3):133-4. [Medline].
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