HISTORY, CURRENT ILLNESS AND PHYSICAL EXAMINATION

History
65-year-old woman with cardiovascular risk factors such as hypertension, dyslipidaemia and active smoking. As personal history, she has a normofunctioning mechanical aortic and mitral prosthesis with preserved ventricular function in outpatient follow-up. She is in permanent atrial fibrillation with frequency control strategy, anticoagulated with sintrom, diagnosed after emboligenic debut in 2014 with episode of transient ischaemic accident without neurological sequelae. She also has unaffiliated chronic kidney disease and moderate polyarticular osteoarthritis. As treatment she takes acenocoumarol 4 mg daily with good control of the usual INR, enalapril 5 mg daily, bisoprolol 10 mg daily, atorvastatin 20 mg daily, omeprazole 20 mg daily and paracetamol and metamizole alternately for joint pain.

Present illness
She presented to the Emergency Department for functional class deterioration 2 weeks after onset. The patient reports dyspnoea that has progressed to rest, orthopnoea previously absent and currently 90 degrees, and paroxysmal nocturnal dyspnoea crisis. She also reports oliguria, oedema up to the knees and a feeling of abdominal distension. He also reported frequent episodes of palpitations and the finding of elevated heart rates of over 100 bpm during his ambulatory blood pressure measurement.

Physical examination
Physical examination revealed blood pressure of 130/80 mmHg, heart rate of 140 bpm, tachypnoea with slurred speech and basal saturation of 89%. She presented jugular venous engorgement up to 1/3 mid-cervical with venous repletion up to the mandibular angle due to positive hepatojugular reflux, crackles up to midfields, moderately distended abdomen with painful hepatomegaly of 3 crossings and with semiology compatible with mild ascites, and oedema up to 1/3 distal thighs.

COMPLEMENTARY TESTS
Electrocardiogram: tracing compatible with atypical atrial flutter with ventricular response at 140 bpm and wide QRS with BCRDHH morphology. Blood tests: haemoglobin 14.4 mg/dl, platelets 226,000, leucocytes 12.100 with normal formula, INR of 3.49, arterial blood gas with pH 7.44, pO2 54, pCO2 36, Sat O2 86 %, lactate 1.9, bicarbonate 29, creatinine 0.89 mg/dl, sodium 142, potassium 4.4, ALT 55, bilirubin 1.6, alkaline phosphatase 267, GGT 99, NTproBNP 5145. Normal C-reactive protein and procalcitonin. Chest X-ray: increased cardiothoracic index. Bilateral pleural effusion and bilateral hilar infiltrate with evidence of vascular redistribution. Transthoracic echocardiogram: mechanical prosthesis in normopositioned mitral position, with mean gradient of 4 mmHg and effective valve area calculated by THP greater than 2 cm2. Mild insufficiency. Mechanical prosthesis in aortic position with maximum gradient of 28 mmHg and mean gradient of 15 mmHg. Mild insufficiency. Morphologically normal tricuspid valve. Mild-moderate insufficiency. Pulmonary artery systolic pressure estimated at 38 mmHg. Left ventricle not dilated, slightly hypertrophic, with severely depressed global systolic function (LVEF 22% by Simpson biplane). Akinesia of the inferior and inferolateral sides, and of the basal and middle segment of the septum. Severe hypokinesia of the rest. Slightly dilated left atrium. Slightly dilated right atrium. Dilated right ventricle, severely hypocontractile. TAPSE: 12 mm. No pericardial effusion. Normal aortic root. Dilated inferior vena cava without inspiratory collapse.

EVOLUTION
Given the situation of respiratory compromise, the patient was transferred to the Acute Cardiac Care Unit, initiating non-invasive ventilatory support with Bi-PAP, intravenous diuretic and frequency control strategy with intravenous digitalisation, with suboptimal control despite blood digoxin levels in the high range of the safety margin, so intravenous amiodarone and beta-blockers at low doses were added to the treatment after a decrease in congestive signs. Heart rate control was achieved, but the patient remained in atrial flutter with a ventricular response of around 85 bpm. An echocardiogram was performed after initial heart rate control, which yielded the results that can be seen in the complementary tests. In summary, severe biventricular dysfunction was observed with evidence of right congestion, with normofunctioning mechanical prostheses. No significant biauricular dilatation. In view of these findings, coronary angiography was performed, ruling out significant coronary artery disease, and global heart failure with biventricular dysfunction secondary to tachycardiomyopathy was postulated as the first diagnosis. Progressively favourable evolution with good frequency control and reduction of respiratory work and improvement of congestive symptoms. Intravenous amiodarone was withdrawn and oral impregnation was maintained, beta-blockers were progressively titrated up to a maximum dose of 10 mg per day and oral digoxin was maintained, with good control. Spironolactone 25 mg per day and furosemide 40 mg in the morning were added to the treatment, maintaining enalapril 5 mg every 12 hours, acenocoumarol and the rest of his usual medication. Finally, after discussing the case with electrophysiology, considering a complex approach for ablation of atypical flutter substrate requiring left access, an endovascular electrophysiological study was rejected and unsuccessful electrical cardioversion was scheduled after the application of 3 shocks. In euvolemic and stable condition, in atypical flutter with controlled ventricular response, she was discharged and referred for follow-up in the Cardiology Day Hospital and heart failure consultation. Subsequent follow-up in the Cardiology day hospital showed the patient to be stable, in functional class II with no evidence of heart failure decompensation. However, she returned to the emergency department of our hospital 2 months later with global heart failure again, reporting palpitations and elevated heart rates on the home blood pressure monitor. The ECG showed the same atypical atrial flutter at 140 bpm. He was again admitted to the Acute Cardiac Care Unit, where non-invasive ventilation, intravenous furosemide and perfused amiodarone were started again, maintaining beta-blockers and digoxin, with a progressively favourable evolution, although it was impossible to control the heart rate, maintaining symptoms and semiology of decompensated heart failure. Considering the patient's tachycardiomyopathy, with severe biventricular dysfunction, and after ruling out another flutter substrate approach due to the need for left access with potential associated complications in an anticoagulated patient, the Heart Team decided to implant a pacemaker-cardiac resynchronisation therapy (CCP-CRT) in the first stage and later ablation of the atrioventricular node. Thus, during admission, endocavitary left cephalic endocardial CRT-PCM was successfully implanted, which allowed subsequent titration of bisoprolol up to supramax doses of 20 mg per day with very good tolerance, achieving good heart rate control and resolution of acute heart failure. Finally, he was discharged in stable, euvolemic condition, maintaining treatment with furosemide 40 mg per day, acenocoumarol 3 mg per day, spironolactone 25 mg per day, enalapril 5 mg every 12 hours, and bisoprolol 10 mg every 12 hours. The following month, and as scheduled, atrioventricular node ablation was performed without incident, and the patient was discharged from the Cardiology day hospital without requiring hospitalisation.
Subsequent follow-up in heart failure consultations was stable, without new episodes of heart failure, with a control echocardiogram at 6 months in which a recovery of left ventricular function (measured by LVEF) of up to 37% was observed, with normofunction of the right ventricle.

DIAGNOSIS
Tachycardiomyopathy secondary to atypical atrial flutter with rapid ventricular response. Severe biventricular dysfunction. Pacemaker implantation-cardiac resynchronisation therapy and nodal ablation. Rheumatic valve disease. Carrier of normofunctioning aortic and mitral valve prostheses.
