A Case of Nonfatal Ventricular Arrhythmia Due to Thyrotoxic Periodic Paralysis in a Saudi Patient as an Initial Presentation of Graves’ Disease

Abstract

Thyrotoxic periodic paralysis (TPP) is a potentially lethal complication of hyperthyroidism characterized by recurrent muscle weakness and hypokalemia. It has been commonly reported in non-Asian populations. Four cases were reported in Saudis so far, and one had a life-threatening arrhythmia. We describe an additional case of a 28-year-old apparently healthy Saudi male patient, who presented with acute paraparesis associated with hypokalemia (K: 2.0 mmol/L), complicated by ventricular tachycardia and cardiac arrest. He was successfully resuscitated and his hypokalemia was corrected. A diagnosis of Graves’ disease associated with TPP was made. He was initially treated with carbimazole and β-blockers and then given a definitive therapy with radioactive iodine, which showed a good response. This case highlights the importance of early recognition and prompt treatment of TPP as a differential diagnosis for muscle weakness. A brief review of TPP and associated arrhythmia is included.

Ventricular Fibrillation

“…According to review of published reports, muscle paralysis seen in these patients mostly manifests with acute proximal symmetrical lower limb weakness, but it can progress to involve all 4 extremities and the respiratory musculature ( 1 , 2 , 3 ). There have been multiple case reports of TPP in the past that manifested with episodes of muscle paralysis with subsequent ventricular arrhythmia, but none whose initial presentation was ventricular arrhythmia ( 4 , 5 ). To our knowledge, this is the first reported case of TPP with an initial presentation of VF.…”

A rare case of hypokalemic ventricular tachycardia in a patient with thyrotoxic periodic paralysis

“…TPP, a state in which proximal, symmetrical ascending muscle weakness in lower extremities occurs in hyperthyroid patients, is a multifactorial condition that involves hypokalemia and a hyperadrenergic state. [127] Pathogenesis still remains unclear, but it is known that a high amount of thyroid hormone present in the body leads to an increased activation and stimulation of channels and genes on the myocardium. Thyrotoxicosis leads to more binding and decreased inactivation of hormones at receptor sites located on tissues, commonly beta-2 adrenergic receptors on muscle cells.…”

“…Therefore, symptoms are usually seen in the morning hours or at rest while after an intense work out and a high-carbohydrate meal. [1] Multiple differential diagnoses for weakness could be neuromuscular junction diseases such as myasthenia gravis and botulism, spinal cord diseases such as poliomyelitis, polyneuropathies like Guillain–Barre syndrome, and primary acute myopathies such as electrolyte abnormalities, myoglobinuria, and alcoholic myopathy. [2]…”

“…It has been shown that with a new onset of hyperthyroidism that presents with paralytic attacks, it is rarely associated with the typical findings normally seen with hyperthyroidism. [17] In the patient presented, typical hyperthyroid symptoms such as palpitations, diarrhea, and heat intolerance were not evident, allowing TPP to be overlooked. Instead, muscle weakness and emesis were the first symptoms of a newly diagnosed hyperthyroidism.…”

“…Thyrotoxic periodic paralysis (TPP) is a condition that appears at an incidence of 2% in patients with thyrotoxicosis, commonly in males of Asian descent, yet not limited to these ethnic groups. [12] It occurs as acute episodes of muscle weakness associated with hypokalemia, which resolves once the hypokalemia is treated and is usually precipitated by exercise, carbohydrate load, or stress. In addition to the paralysis, complications resulting from TPP include arrhythmias, respiratory problems, especially hypercapnic respiratory failure, and death.…”