Hypertrophic obstructive cardiomyopathy, yamaguchi syndrome and kounis syndrome: Clinical challenges.

The Editor,

In the interesting report concerning the case of an apical variant of hypertrophic cardiomyopathy also called as Yamaguchi syndrome published in Annals of Cardiac Anesthesia,[1] the authors stated that anesthetic management of these patients is similar to case of hypertrophic obstructive cardiomyopathy. Therefore, alleviating sympathetic stimulation such as avoiding tachycardia, maintaining normal sinus rhythm and euvolemia, and avoiding any increase in cardiac contractility is helpful. However, serious challenges concerning anaphylaxis, labor, anesthesia, and surgery should be always considered in anesthesia and surgery.

Anaphylaxis creates increase heart rate, increase myocardial contractility, decrease preload, and decrease afterload due fluid extravasation that exacerbates left ventricular outflow obstruction. Hypertrophic cardiomyopathy is correlated genetically with atopic diathesis, whereas involved genes predispose to eosinophilic esophagitis manifesting with chest pain as a primary symptom.[2] Patients with obstructive cardiomyopathy may demonstrate hypersensitivity myocarditis toward the administered drugs, a life-threatening but also a potentially treatable complication.[3]

Anaphylaxis can induce coronary spasm, the so-called type I of Kounis hypersensitivity-associated acute coronary syndrome that aggravates preexisting myocardial ischemia. Hypertrophic cardiomyopathy coexistence with coronary spasm plays a significant role in myocardial ischemia induction, a commonly encountered feature of the disease. Especially, coronary vasospasm was induced in 10 out of 36 (28%) hypertrophic cardiomyopathy patients who had undergone challenging with acetylcholine provocation test.[4]

In anesthesia, β-adrenergic agents, dopamine, dobutamine, epinephrine, and isoproterenol, contribute to obstruction worsening due to their positive inotropic and chronotropic effects, while α1-adrenergic agonist, phenylephrine, reduces obstruction through systemic vascular resistance reduction.

Major blood loss during labor could further aggravate obstruction by preload decrease and reflex tachycardia provocation. While oxytocin reduces the systemic vascular resistance (SVR) and increases the heart rate, ergometrine increases the SVR and appears to have beneficial impact on these patients.[5]

Therefore, anesthetists, surgeons, and physicians in general should be aware that patients with hypertrophic cardiomyopathy pose unique challenges. Adequate preload, control of sympathetic stimulation, control heart rate, and increased afterload are of paramount importance.

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