Intermittent hypoxia and ventilatory intermittence due to sleep disorders such as obstructive sleep apnea can lead to cardiac arrhythmia, coronary artery disease, conductance disturbances and cardiac failure. Sub-clinical and overt hypothyroidism is an important physiopathological complex that is linked with cardiovascular risk, alteration of lipidic profile promoting atherogenic mechanisms. The two pathologies combined can exponentially increase the cardiovascular event risk. This case report demonstrates a young patient with obesity and arterial hypertension accusing irregular heart beats. Despite a normal resting ECG and echocardiography the patient presented malignant ventricular arrhythmias revealed on the 24h Holier ECG. The Epworth scale was 20 and the patient presented numerous episodes of hypopnea with an increased apnea-hypopnea index associated with ventricular arrhytmias on the polisomnography. The endocrine profile of the patient revealed a sublinical hypothyroidism that untreated can lead to accelerated atherosclerosis and arrhytmic risk. CPAP treatment alongside the levothyroxine treatment at TSH levels above 10mUI/L have controlled the malignant arrhythmic events without complex antiarrhythmic drugs sustaining the pathogenic contributions of this two pathologies in arrhythmogenesis process.