A 75-year-old male patient was referred to the emergency department from the outpatient cardiology department for significant clinical deterioration, with dyspnoea on minimal effort, orthopnoea, paroxysmal nocturnal dyspnoea and palpitations.

History, current illness and physical examination

History
No known drug allergies.
Risk factors: diabetes mellitus 2, hypertension, dyslipidaemia. Ex-smoker for 7 years of 50 packs/year.
Medical history: COPD. Ischaemic stroke of middle cerebral artery in March 2008. Surgical interventions: haemorrhoids, epigastric hernia, colonic polypectomy. Bladder tumour treated with TUR in 2011 and 2013.
Previous heart disease: dilated cardiomyopathy diagnosed in 2002 with severely depressed systolic function (LVEF 20%), and normal coronary arteries in cardiac catheterisation. Follow-up in cardiology outpatient clinics, with significant improvement in ventricular function with medical treatment (LVEF 50% in echocardiograms in 2008, 2010 and 2012). In November 2013, she presented with atrial fibrillation with rapid ventricular response, electrical cardioversion was performed in the emergency department, which was effective and she was discharged. A week later, he returned to the emergency department for atrial fibrillation, where electrical cardioversion was again performed, and he was discharged to sinus rhythm. On review at the outpatient clinic in January 2014, the patient was again in atrial fibrillation.

Usual treatment: dabigatran 110 mg/12h, bisoprolol 10 mg/24h, ramipril 2.5 mg/24h, rosuvastatin 20 mg/24h, omeprazole 40 mg/24h, furosemide 20 mg/12h (administered as needed), inhaled tiotropium bromide, repaglinide 0.5 mg, fluoxetine 20 mg, alprazolam 0.5 mg/24h.

Present illness: 75-year-old male patient referred to the emergency department from the cardiology outpatient department for presenting significant clinical deterioration in recent weeks, with dyspnoea on minimal exertion, orthopnoea, paroxysmal nocturnal dyspnoea, and palpitations in recent days. He did not report any respiratory infection or other accompanying symptoms. On admission, he presented atrial fibrillation with ventricular response at 130-150 bpm despite treatment with maximum doses of beta-blockers, so he was referred for admission to cardiology to attempt rate control or cardioversion.

Physical examination
BP 120/65 mmHg. HR 155 bpm, Ta 36.5 oC. O2 Sat. O2 96% with FiO2 of 0.21.
Patient conscious, normal colour and normohydrated.
Cardiac auscultation: arrhythmic cardiac tones, without murmurs.
Pulmonary auscultation: generalised decrease in vesicular murmur, with bibasal crackles. lower limbs: no oedema, no signs of deep vein thrombosis.
Abdomen: soft, not painful on palpation.

Additional tests
ECG: atrial fibrillation with rapid ventricular response, narrow QRS, no intraventricular conduction disturbances. Signs of left ventricular overload in V5-V6 and DI and aVL.
Chest X-ray: bibasal alveolar interstitial infiltrates suggestive of heart failure. Free costophrenic sinuses. Cardiothoracic index less than 0.5.
Blood tests carried out on the cardiology ward: ʟʟ Leucocytes: 12.4x10e9/L, Hb17.5 g/dl, platelets 262x10e9/L.
Coagulation: PTT 15s, IQ: 76%, APTT 35.3s.
Glucose: 140 mg/dl, urea 64 mg/dl, creatinine 1.21 mg/dl, K 5 MM/L, Na 143 MM/L, AST 31 U/L, ALT 41 MM/L, LDH 244 U/L, CRP 0.2 mg/dl, pro-BNP 16727 pg/ml.
Glycosylated haemoglobin: 6.9%.

Echocardiogram:
Poor echocardiographic window.
Left ventricle slightly dilated, not hypertrophic, with severely depressed global contraction (20-25%), severe apex hypokinesia.
Moderately dilated left atrium.
Mitral valve thickened, with mild insufficiency.
Sclerosed aortic valve, with good opening, without insufficiency.
Right chambers with moderately dilated atrium. Preserved RVEF.
Inferior vena cava not dilated, with good inspiratory collapse.
No pericardial effusion.

Clinical evolution
The patient was admitted to the cardiology ward with atrial fibrillation with ventricular response at 140-150 bpm without being able to control it despite increasing bisoprolol to a dose of 15 mg/24h and adding digoxin and amiodarone, remaining with a ventricular rate of 130-140 bpm for the following 3 days. Given the failure of rhythm control in previous episodes and difficult heart rate control, the clinical team, electrophysiologists and the family decided together to ablate the atrioventricular node and place a pacemaker. A permanent pacemaker was placed, with the intention of also placing an LV lead for cardiac resynchronisation therapy (CRT), but this was not possible due to coronary sinus dissection. Finally, a DDD pacemaker was placed. Five days later, atrioventricular node ablation was performed without incident. The patient was discharged with better clinical control, maintaining the same anticoagulant treatment, withdrawing digoxin, amiodarone and the very high doses of bisoprolol with which he had tried to reduce the heart rate. Medication for the management of heart failure was maintained.

Diagnosis
Atrial fibrillation with difficult to control rapid ventricular response.
Rate control strategy by AV node ablation and pacemaker implantation.
Tachycardiomyopathy with severe ventricular dysfunction.
