Background: Tachycardiomyopathy is a non-familial cause of heart failure that can be reversible. A high index of suspicion is necessary for its diagnosis and for a rational approach in the management of patients. Aims: To describe the clinical profile and verify the treatment and outcome of a series of cases of patients with tachycardiomyopathy. Methodology: Among patients without previous ventricular dysfunction, those with tachycardiomyopathy were identified. They underwent clinical evaluation, complementary diagnostic tests, treatment and clinical follow-up. Results: 10 patients had tachycardiomyopathy, mean age 64.5 ± 11.5 years, 6 women. The arrhythmias were atrial fibrillation with a high heart rate (80%); atrial tachycardia with high heart rate and frequent ventricular premature beats. Mean baseline heart rate was 110.2 bpm and the ejection fraction was 36.8%. For heart rate control, all were treated with beta-blockers, in association with digoxin in 6 patients. It was necessary to implant a pacemaker in VVI mode        (V: ventricle is stimulated, V: ventricle sensed; I: inhibiting response) and ablation of the atrioventricular node in 2 patients with persistent atrial fibrillation. After a mean 27.6 months, the mean heart rate was 76.5 bpm (p <0.0001, paired t-test) and there was clinical improvement of all patients. There was an average increase of 9.6% in the left ventricular ejection fraction. Despite this, 4 patients still had ventricular dysfunction (3 of them developed comorbidities). Conclusion: In this series, the main cause of tachycardiomyopathy was atrial fibrillation with high heart rate. Similar to the description of literature, there was remission of symptoms with restore normal heart rhythm or control heart rate.