An inherited disorder with paroxysmal tachycardia, arterial hypertension, syncope, and seizures. It is associated with microphthalmos, cataracts, and nephrolithiasis.
This medical condition has been described in a female, her brother, and mother in 1967.
Autosomal recessive inheritance seems likely, but in the absence of male-to-male transmission, X-linkage cannot be excluded.
Characterized clinically by frequent episodes (initially once per week with the duration ranging from minutes to days, later more frequent) of paroxysmal tachycardia (due to a conduction defect, with heart rates of up to 220 beats per minute), chest pain, dyspnoe, cyanosis, syncope, severe arterial hypertension, and generalized tonic-clonic seizures all more or less refractory to treatment at that time. Additional findings may include dominantly inherited hyperglycinuria with nephrolithiasis, microphthalmos, cataracts, glaucoma, visual loss, bilateral horizontal and rotary nystagmus, and subcutaneous lipomas. Similar symptoms were found in the younger brother, but with decreased severity. The mother also suffered from congenital microphthalmia, cataracts, and nystagmus. At the age of 44 years she was diagnosed with calcium oxalate and calcium phosphate kidney stones. The patient died at the age of 35 years from sudden apnea followed by ventricular fibrillation and cardiac arrest 28 hours after cardiac surgery for arrhythmias and pacemaker implantation.
Precautions before anesthesia
Obtaining a cardiology consultation is recommended. A 12-lead ECG, chest radiograph, and echocardiography should be available. Evaluate for end-organ damage as a result of chronic hypertension. A complete blood count, serum concentrations of electrolytes, urea, creatine, and glucose should be determined before anesthesia. Patients are at risk for paroxysmal supraventricular tachycardia (usually sinus tachycardia) in the perioperative period. Severe hypertensive episodes may be encountered and maintenance of antihypertensive therapy must be maintained until the morning of anesthesia. Consider preoperative beta-blockers, calcium channel blockers, and/or angiotensin converting enzyme (ACE) inhibitors before general anesthesia. Hypertension must be controlled before undergoing elective surgery. Because of the presence of arterial hypertension, it is important to ensure that the intravascular volume is adequate before induction of anesthesia. A review of the medications used to control seizure activities must be obtained. The anti-seizure medications must be continued until the morning of surgery.
Cardiac conduction defects, (ie, paroxysmal supraventricular tachycardia, sinus tachycardia, atrioventricular block) and severe arterial hypertension can lead to major complications during anesthesia. Electrical and pharmacological cardioversion should be readily available as they may be required. Arterial hypertension should be managed perioperatively. Patients may have relative an intravascular volume deficit as a result of arterial hypertension and should be corrected before induction of anesthesia. Because of the high risk for arrhythmias, careful handling of guide-wires during central venous line access is recommended (the same applies for peripherally inserted central catheters, cardiac catheter procedures, or transjugular intrahepatic liver biopsies).