Kounis Syndrome: Diagnosis (Part 2 of 4)

Separating the symptoms of the coronary syndrome from those caused by the coincident allergic reaction is difficult.  Acute chest pain is the hallmark symptom of Kounis Syndrome. While other symptoms may be present, such as nausea, fainting, and shortness of breath, they can also be attributed to the allergic reaction.  Likewise, many of the clinical markers for KS may also appear during anaphylaxis, including cold extremities, very fast or very low heart rate, low blood pressure, palpitations, and sweating. Given the significant overlap in presentation with allergic symptoms, KS is not often diagnosed, though it likely affects a larger population than represented in literature.

Troponins and cardiac enzymes like creatinine kinase are important markers for coronary syndrome, but they are not always elevated in KS. Measurement of mast cell mediators like histamine or tryptase is not always accurate due to the short lifetime of these molecules in the body.  Released histamine is only present in blood for about eight minutes, while tryptase has a half-life of about ninety minutes.

An electrocardiogram (EKG) should be performed as part of the diagnostic process.  A number of signs have been seen in KS patients, including atrial or ventricular fibrillation, bigeminal rhythm, heart block, nodal rhythm, sinus bradycardia or tachycardia, ST segment depression or elevation, T-wave flattening or inversion, QRS or QT prolongation, and ventricular ectopics.  Beyond EKG, there are additional markers that may be present with Kounis Syndrome.  A chest x-ray may show an enlarged heart.  Echocardiogram may show dilated cardiac chambers. Angiography of the coronary artery can reveal spasm or thrombosis. In coronary biopsies, infiltration by mast cells and eosinophils may be found.  Elevation of eosinophils in the blood may also be present.

Having no history of coronary artery disease can make diagnosis more complicated for KS Type I patients, who also may have normal troponins and EKG. Dynamic cardiac MRI with gadolinium can show a subendocardial lesion in patients with KS Type I. Newer imaging techniques such as SPECT have been able to identify myocardial ischemia in KS Type I where coronary angiography had showed no irregularities.

References:

Kounis NG, et al. Kounis Syndrome (allergic angina and allergic myocardial infarction). In: Angina Pectoris: Etiology, Pathogenesis and Treatment 2008.

Lippi G, et al. Cardiac troponin I is increased in patients admitted to the emergency department with severe allergic reactions. A case-control study. International Journal of Cardiology 2015, 194: 68-69.

Kounis NG, et al. The heart and coronary arteries as primary target in severe allergic reactions: Cardiac troponins and the Kounis hypersensitivity-associated acute coronary syndrome. International Journal of Cardiology 2015, 198: 83-84.

Fassio F, et al. Kounis syndrome: a concise review with focus on management. European Journal of Internal Medicine 2016; 30:7-10.

Kounis Syndrome: Aspects on pathophysiology and management. European Journal of Internal Medicine 2016.

Kounis NG. Kounis syndrome: an update on epidemiology, pathogenesis, diagnosis and therapeutic management. Clin Chem Lab Med 2016

Kounis NG. Coronary hypersensitivity disorder: the Kounis Syndrome. Clinical Therapeutics 2013, 35 (5): 563-571.

1 Response

  1. Mark May 16, 2016 / 6:04 am

    FWIW — unless and until we get coherent, reliable info otherwise, I’m going to wonder if Prince was another victim of Kounis Syndrome. Joining, I believe, Michael Jackson, Joan Rivers, Christopher Reeves, who knows who else besides those properly diagnosed. As ultimately, 2 or all 3 of these victims may have been.

    Unfortunately, autopsy analysis impt to this determination may not have been performed, and we will learn no more from a cremated body.

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