A 79-year-old man with obesity, arterial hypertension (AHT), type 2 diabetes mellitus, ischaemic heart disease, AF, chronic obstructive pulmonary disease (COPD) and sleep apnoea syndrome. She came to the primary care clinic for dizziness with a sensation of spinning objects, especially when walking, which subsided at rest. She reported an increase in her usual dyspnoea. She had no loss of consciousness, chest pain, vomiting or cold sweats. He was receiving regular treatment with amlodipine, repaglinide, nitroglycerin (patches), acenocoumarol, atorvastatin, atenolol, acetylsalicylic acid, spironolactone, isophane protamine insulin, paracetamol-tramadol and omeprazole, with good compliance.
Physical examination revealed the presence of arrhythmia on cardiac auscultation, with slow, muffled tones and no murmurs. Radial pulses were present and symmetrical. Pulmonary auscultation shows generalised hypoventilation, with no extra sounds. The neurological examination is strictly normal. There was oedema with fovea up to the knees and signs of chronic venous insufficiency in the lower limbs. Using a pulse oximeter, we detected a heart rate of 30 beats per minute (bpm) and an oxygen saturation of 90%.
In view of the patient's symptoms (dizziness with a sensation of spinning objects, with no other added symptoms) and the heart rate detected, it was decided to perform an ECG.

After evaluating the ECG, and given the patient's personal history (hypertension, ischaemic heart disease), we compared the recording obtained with a previous ECG, taken three years earlier during an admission for an episode of exacerbation of COPD.

Comparing both electrocardiographic recordings, it was found that there was no bradycardia and that the QRS complexes now appeared rhythmic, but no P waves were seen, so, in view of the ECG obtained and the clinical findings, it was decided to refer the patient to the Hospital Emergency Department.
With a suspected diagnosis of slow AF, negative chronotropic treatment was withdrawn, with no improvement. Given the lack of response to this measure, it was decided to admit the patient to Cardiology. After a complete study, a definitive diagnosis was made of AF with advanced atrioventricular block and right bundle branch block grade III, symptomatic, and a permanent pacemaker was implanted. The patient evolves favourably: the clinical symptoms disappear and the heart rate is controlled.