Dysplasia of the tricuspid valve leading to recurrent atrial flutter and fibrillation: a case report

Abstract

Background: Atrial flutter (AFL) is usually effectively treated by cavotricuspid isthmus (CTI) ablation. If AFL recurs despite ablation, there is risk of progression to atrial fibrillation (AF) and clinicians should consider underlying structural heart diseases. This consideration becomes especially critical when right-heart-chambers are dilated.

Case summary: A 50-year-old man presented with palpitations due to AFL. Fifteen years earlier, after polytrauma, mild tricuspid regurgitation (TR) and pericardial effusion had been diagnosed on transthoracic echocardiography (TTE). At present, TTE showed dilated right-heart-chambers and moderate TR. Despite two CTI-ablations, he developed AF for which he underwent pulmonary vein isolation (PVI). A further ablation was performed because of right-sided AFL due to transcrista conduction. Atrial fibrillation recurred, accompanied by heart failure. Tricuspid regurgitation severity and right-heart-chamber dilatation worsened. Finally, 3D-transoesophageal echocardiography (3D-TEE), performed 20 years after the first TTE, revealed that TR was due to restriction of the septal leaflet. The patient underwent surgery. The tricuspid valve was repaired by ring annuloplasty and a cleft between the anterior and septal leaflets was closed. Three years post-operatively, he is asymptomatic with chronic AF but no recurrent AFL. Transthoracic echocardiography shows only mild TR, though the right-heart-chambers remain dilated, likely due to long-standing TR.

Discussion: Tricuspid regurgitation and AFL/AF have a bidirectional relationship. Tricuspid regurgitation can both cause and result from AFL/AF. Structural heart diseases, including post-traumatic valve damage, should be considered in patients with recurrent AFL despite CTI-ablation and progression to AF. In cases with TR and right-heart-chamber enlargement, 3D-TEE is essential for accurate diagnosis and should be performed without delay.

Keywords: 3D-echocardiography; Atrial fibrillation; Atrial flutter; Cavotricuspid isthmus ablation; Tricuspid valve regurgitation.

Figure 1

Summary of the time course over 22 years, starting with a car accident at the age of 35 years. Lightning, electrical or medical cardioversion; y, age in years; mo, months; AFL, atrial flutter; AF, atrial fibrillation; cMR, cardiac magnetic resonance tomography; CTI, cavotricuspid isthmus; PVI, pulmonary vein isolation; ECG, electrocardiogram; EPS, electrophysiological study; TEE, transoesophageal echocardiography; TTE, transthoracic echocardiography; 3D-TEE, three-dimensional transoesophageal echocardiography; RA, right atrium; RV, right ventricle; TR, tricuspid regurgitation.

Figure 2

Electrocardiograms and electrophysiologic findings, registered during the first ablation. (A) The 12-lead electrocardiogram shows atrial flutter with a ventricular frequency of 70 bpm, normal axis, incomplete right bundle branch block, and normal repolarization. The atrial activation shows a sawtooth pattern with a cycle length of 270 ms, negative in inferior leads, with a slow downward slope followed by a fast upward slope, and a positive F-wave in V₁. (B1) Intracardiac electrocardiogram of atrial flutter induced during cavotricuspid isthmus (CTI) ablation. The activation, registered by the halo catheter, is depicted as a yellow arrow and runs from the proximal to the distal part. The activation registered by the coronary sinus (CS)-catheter is depicted by the blue arrow and runs from the proximal to the distal part. The signals at the coronary sinus-catheter are partly not registered because of poor contact due to the dilatation of the right atrium and the coronary sinus. The ablation catheter (red point) is placed in the cavotricuspid isthmus. HIS, his bundle; RF, ablation catheter; Halo, 20-pole halo catheter positioned in the right atrium along the tricuspid ring. (B2) Fluoroscopic picture in LAO (left anterior oblique) 50° projection with schematic drawing of the activation, as recorded in (B1). The yellow arrow shows the activation running counterclockwise around the tricuspid valve (TV). The broken yellow arrow is the assumed activation around the tricuspid valve. The blue arrow shows the activation running from the proximal part to the distal part of the coronary sinus-catheter. The red point shows the tip of the RF catheter placed on the cavotricuspid isthmus. The white broken line indicates the assumed activation passing the cavotricuspid isthmus. (C1) Intracardiac ECG recorded at the end of the first cavotricuspid isthmus ablation during pacing from the proximal pole of the coronary sinus-catheter. The green star indicates the point of pacing. The activation on the Halo catheter runs from the proximal part to distal with an activation time from coronary sinus to cavotricuspid isthmus measured 202 ms. Double potentials (the orange and the yellow triangles) are also recorded on the RF-catheter with the time between the two signals measured 183 ms. (C2) Fluoroscopic picture in LAO 50° projection with schematic drawing of the activation, as recorded in (C1). The green star shows the site of pacing. The long activation time of 202 ms from the proximal coronary sinus to distal Halo reflects that the cavotricuspid isthmus line (where the RF catheter is positioned) is blocked. The first farfield-signal recorded on the RF-catheter (orange triangle) indicates early activation septal from the cavotricuspid isthmus line and the second farfield-signal (yellow triangle) lateral from the cavotricuspid isthmus line. The long time (183 ms) between the two signals is a proof, that the cavotricuspid isthmus line is electrically blocked. (D) Voltage map of the right atrium in anterior–posterior projection. The purple colour indicates a voltage >0.5 mV, which is considered to be normal. The red points are the ablation points. His indicates the place where the His-potential was recorded. SVC, superior vena cava; IVC, inferior vena cava; CTI, cavotricuspid isthmus; TV, tricuspid valve.

Figure 3

Cardiac magnetic resonance tomography in the end-diastolic phase (left) and in the end-systolic phase (right) shows significant dilatation of both the right atrium and right ventricle. Cine imaging is available in the supplementary material online. ra, right atrium; rv, right ventricle; la, left atrium; lv, left ventricle.

Figure 4

Tricuspid valve in the 3D-transoesophageal echocardiography (A) and in the 2D-transoesophageal echocardiography (B and C with colour Doppler) in the end-diastolic phase shows restriction of the septal leaflet, the regurgitant orifice (star), and the jet. Video clips are available in the supplementary material online. al, anterior leaflet; sl, septal leaflet; pl, posterior leaflet; ra, right atrium; rv, right ventricle.

Figure 5

Intraoperative picture of the tricuspid valve seen from the right atrium. The cleft (arrow) is held closed with tweezers and the clamp. al, anterior leaflet; sl, septal leaflet.