Right Atrial Diverticulum Presenting as WolffParkinson-White Syndrome ROBERT M. CAMPBELL,* W. JAMES PARKS,* FRED A. CRAWFORD,** and PAUL C. GILLETTE+ From *The Children's Heart Center. Egleston at Emory, Atlanta, Ceorgia, **the Medical University of South Carolina, Department of Cardiovascular Surgery, and tthe Division of Pediatric Cardiology, Charleston, South Carolina CAMPBELL, R.M., ET AL.: Right Atrial Diverticulum Presenting as Wolff-Parkinson-White Syndrome. A
7-year-oJd male presenting with Woi/_f-Parkinson-Whife syndrome and tachycardia was suspected by echocardiographic and magnetic resonance imaging evaluation to have an associated pericardial cyst anterior to the right atrium and ventricle. ElectrophysioJogical evaluation demonstrated short antegrade and retrograde accessory connection refractory periods, with inducibleorthodromicatrioventricular reentrant tachycardia. Surgical observation revealed a rare congenital right atrial diverticulum bridging the anterior right atrioventricular groove, with the functional accessory connection Jateralized to the medial aspect of this structure. Endocardia! and epicardial incisions and cryoJesions placed along the anterior right atrioventricular groove initially appeared successful, but preexcitation recurred within 4 weeks posfoperatively. (PACE, Vol. 15, August 1992) Wolff-Parkinson-White syndrome, right atriaJ diverticulum
Introduction Tbe pattern of Wolff-Parkinson-White preexcitation results from direct muscular connection between the atrium and ventricle with an accessory connection. The accessory connection may be made of normal working atrial or ventricular myocardium, but may also consist of specialized myocardial cells resembling the normal atrioventricular (AV) node. We present here a case of a rare congenital right atrial diverticulum that bridged the right AV groove and presented as Wolff-Parkinson-White syndrome. Case Summary CO., a 7V2-year-old male, first presented in March 1989, for evaluation of possible tachycar-
Address for reprints; Robert M. Campbell, M.D,, The Cbildren's Heart Center. 2040 Ridgewood Drive NE. Atlanta. GA 30322, Fax: (404) 248-5110, Received February 12. 1992; revision April 16. 1992: accepted May 5, 1992.
PACE, Vol. 15
dia, noted initially 2 months previously. There had been no history of any perinatal tachycardia or any other arrhythmia-related complaints. Family history was negative for congenital heart disease or any tachycardias. Physical examination revealed a weight of 49 pounds and normal vital signs. Cardiovascular exam was within normal limits revealing only a grade II/VI innocent systolic ejection murmur along the left lower sternal border. Electrocardiogram (ECC) showed evidence for sinus rhythm and Wolff-Parkinson-White syndrome (Fig. 1). Subsequent transtelepbonic monitoring documented the presence of a narrow QRS supraventricular tachycardia (SVT) that was associated with mild shortness of breatb. Craded exercise treadmill test generated a maximum sinus rate of 200 beats/min with persistence of the ventricular preexcitation pattern. No symptoms or SVT developed during exercise testing. Echocardiographic evaluation revealed the suprising finding of a fluid-filled density either within the right ventricular cavity or anterior to the right ventricle, questionably representing a pericardial cyst. Dop-
August 1992
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CAMPBELL, ET AL.
Figure 1. Baseline 12-lead ECG demonstrating sinus rhythm with ventricular preexcitation, consistent with a right anterior accessory connection.
pier echocardiography detected no flow within this cavity. There was no displacement of the tricuspid valve to suggest Ebstein's anomaly. The remainder of intracardiac anatomy, function, and Doppler was within normal limits. ECG-magnetic resonance imaging (MRI) likewise demonstrated a fluid-filled density bridging the right AV groove (Fig. 2). There was no displacement of the tricuspid valve. Because of the echocardiographic and MRI findings, the exercise study suggesting short antegrade accessory connection refractory period, and the recurrent clinical episodes of SVT, cardiac catherization and formal electrophysiological study was recommended. During hemodynamic catheterization, normal right heart pressures and saturations were recorded. Right ventricular cineangiogram performed in the anterior-posterior and lateral projection showed a filling defect located along the anterolateral right ventricular horder. Electrophysiological study was consistent with a right anterior accessory connection, with short antegrade (< 170 msec) and retrograde (170 msec) refractory periods. Narrow QRS orthodromic AV reentrant tachycardia (cycle length [CL] = 300 msec) could be repeatedly induced with evidence during SVT for earliest atrial activation along the anterior right
1102
atrium. Nonsustained atrial flutter (atrial CL = 200 msec) with 1:1 accessory connection conduction was associated with profound hypotension. Because of the potentially dangerous electrophysiological properties of the accessory connection, surgical division of the accessory connection was recommended. A median sternotomy was performed; there was no evidence for a pericardial cyst. External inspection of the heart showed separate right and left atrial appendages as well as an anterior hlood-filled mass located between the right atrium and right ventricle. The mass appeared to arise from the anterior right atrium, crossing the right AV groove and connecting to the anterior right ventricular free wall. The color and appearance was that of a normal atrial myocardium. Aspiration of this cavity revealed low pressure venous blood. Intraoperative saline contrast echo performed by way of the internal jugular catheter was inconclusive. Epicardial mapping during right atrial and right ventricular pacing lateralized the functional accessory connection to the anterior right atrium, along the medial aspect of this structure. Cardiopulmonary bypass was instituted, the patient was intentionally fibrillated, and the patent foramen ovale suture closed. Endocardial right atrial mapping was performed during induced
August 1992
PACE, Vol. 15
RIGHT ATRIAL DIVERTICULUM
Dinv HOSPltl C 36-47-18 ix no 5 ll-OCT-W
SI Th
5.8
tlo of ntis 2
n SE 705 Tr.q.del 176 transu Offc An?
LR
-4 V
UU 2328 64 UL ^36 32
Philips 6vroscar)
Figure 2. Tmnsaxial view of right atriai diverticuJum. Spin echo transaxial magnetic resonance image of a three-chambered view o/the heart illuslrafing right afrial diverticulum (dj, traversing (he afrioventricular groove. Right ventricular/ree-vvaJI indentation and a normal tricuspid value are present, a = right atrium; r = right ventricle; I - left ventricJe; and c - coronary sinus. *MRI done on Philips Gyroscan 1.5 Tesla (Philips Medical Systems, Shelton, CT, USAj at Emory University Department of Radiology, Atlanta, Georgia. Cooperative collaboration ivith Roderic 1. Pettigreiv, M.D., Ph.D., Assistant Professor of Hadiology, and W. fames Parks, M.D., Assistant Professor of Pediatrics, Pediatric Cardiologist, Assistant Professor of Radiology.
SVT with evidence for earliest atrial activation along the anterior right atrium, near the medial aspect of the mass. The patient was cooled and cardioplegia administered. At this time, further inspection of the right atrial endocardium detected the orifice of a right atrial diverticulum. Surgical options were discussed. It was felt potentially hazardous to attempt amputation of the right atrial diverticulum, due to possible daniage to the right coronary artery running beneath the diverticulum in the right AV groove. For this reason, an incision was made approximately 2 mm away from the tricuspid valve annulus extending approximately 180° around the tricuspid valve annulus to the right free-wall region. The AV groove fat pad was identified but appeared to be primitive and the dissection was extended
PACE. Vol. 15
out onto the right ventricular free wall for approximately 1 cm until it became apparent that further dissection would result in entry into the diverticulum. Thus the dissection was prevented from extending to the epicardial surface. An additional epicerdial incision was made at the point of the reflection of the fat pad up onto the diverticulum from the right ventricle. There appeared to be no safe way to satisfactorily resect the diverticulum without potential damage to the underlying coronary artery. Accordingly, a series of overlapping cryolesions at -70°G for 90 seconds each were placed throughout the extent of the junction of this diverticulum with the right ventricle in the region of earliest activation. Additional lesions were placed at both ends of the endocardial and epicardial incisions. The incisions were then sutured
August 1992
1103
CAMPBELL, ET AL.
closed and the atrium w^as closed. The patient was weaned from cardiopulmonary bypass and sinus rhythm reestablished with evidence for intact AV conduction, mild first-degree AV block, and no evidence for ventricular preoxcitation. Right ventricular pacing showed no VA conduction. Early postoperative recovery was uneventful, with no evidence for recurrent preexcitation or SVTs. However, within 4 weeks ECG preexcitation returned, matching the preoperative pattern. Follow-up electrophysiological evaluation revealed inducible orthodromic AV tachycardia with CL 290 msec, using a right anterior accessory connection as the retrograde limb. The accessory connection ERP was < 240 msec antegrade and < 230 msec retrograde. Induced atrial fibrillation resulted in hypotension with a short preexcited RR interval of 210 msec. A second attempt at operative repair was recommended to the family; at this time, they have opted for no further surgical intervention.
Discussion This report deals with a rare congenital right atrial diverticulum that crossed the right AV groove and functioned as an accessory connection supporting Wolff-Parkinson-White preexcitation and its associated tachycardias. True atrial diverticulum is a rarely reported lesion, which must be differentiated from symmetrical dilatation of the atrium. Diverticula have heen noted from the right and left atria.^^^ Morrow and Behrendt^ reported a congenital right atrial aneurysm associated with
recurrent tachycardia and significant decrease in cardiac output in a 23-year-old female. The ECG mechanism of the tachycardias was atrial flutter and atrial fibrillation. Normal sinus rhythm resumed immediately following amputation of the diverticulum. To our knowledge, the association between right atrial diverticulum and the Wolff-ParkinsonWhite syndrome has not been reported. Lack of histologic evaluation in this case does not allow us to differentiate between a direct myocardial connection or the presence of a true accessory connection. The etiology of this patient's diverticulum is unclear; however, this case must represent more than just a simple outpouching from the right atrium, due to the obvious direct electrical connection to the anterior right ventricle. Congenital ventricular diverticula presenting with premature ventricular complexes, accelerated idioventricular rhythm, and ventricular tachycardia have been reported both the right and left ventricles.''•^ Pathologically, these diverticula are classified as either fibrous or muscular. In terms of etiology, these lesions may result from congenital pericardial cysts or a weakness in the ventricular muscle. This represents the first description of an atrial diverticulnm using MRI techniques. Because of the anterior substernal position of this diverticulum, echocardiographic evaluation was never completely definitive. MRI suggested that the diverticulum crossed the AV groove, offering the first clue that this undefined lesion perhaps contributed to the patient's electrical pattern of preexcitation.
References 1. Petit A, Eicher JC, Louis P. Congenital diverticulum of the right atrium situated on the floor of the coronary sinus. Br Heart } 1988; 59:721723. 2. Pitts RM. Potts WJ. Congenital diverticulum of the left atrium. Arch Surg 1962; 84:82-84. 3. Morrow AG, Behrendt DM. Congenital aneurysm (diverticulum) of the right atrium; clinical manifes-
1104
August 1992
tations and results of operative treatment. Circulation 1968; 38:124-128. Shen EN, Fukuyama O, Herre JM, et al. Ventricular tachycardia with congenital ventricular diverticulum. Chest 1991; 100(l):283-285. Hamaoka K, Sawada T. Isolated congenital right ventricular diverticulum with ventricular premature complexes. Am ] Cardiol 1988; 61(6):480-481.
PACE, Vol. 15
7-year-oJd male presenting with Woi/_f-Parkinson-Whife syndrome and tachycardia was suspected by echocardiographic and magnetic resonance imaging evaluation to have an associated pericardial cyst anterior to the right atrium and ventricle. ElectrophysioJogical evaluation demonstrated short antegrade and retrograde accessory connection refractory periods, with inducibleorthodromicatrioventricular reentrant tachycardia. Surgical observation revealed a rare congenital right atrial diverticulum bridging the anterior right atrioventricular groove, with the functional accessory connection Jateralized to the medial aspect of this structure. Endocardia! and epicardial incisions and cryoJesions placed along the anterior right atrioventricular groove initially appeared successful, but preexcitation recurred within 4 weeks posfoperatively. (PACE, Vol. 15, August 1992) Wolff-Parkinson-White syndrome, right atriaJ diverticulum
Introduction Tbe pattern of Wolff-Parkinson-White preexcitation results from direct muscular connection between the atrium and ventricle with an accessory connection. The accessory connection may be made of normal working atrial or ventricular myocardium, but may also consist of specialized myocardial cells resembling the normal atrioventricular (AV) node. We present here a case of a rare congenital right atrial diverticulum that bridged the right AV groove and presented as Wolff-Parkinson-White syndrome. Case Summary CO., a 7V2-year-old male, first presented in March 1989, for evaluation of possible tachycar-
Address for reprints; Robert M. Campbell, M.D,, The Cbildren's Heart Center. 2040 Ridgewood Drive NE. Atlanta. GA 30322, Fax: (404) 248-5110, Received February 12. 1992; revision April 16. 1992: accepted May 5, 1992.
PACE, Vol. 15
dia, noted initially 2 months previously. There had been no history of any perinatal tachycardia or any other arrhythmia-related complaints. Family history was negative for congenital heart disease or any tachycardias. Physical examination revealed a weight of 49 pounds and normal vital signs. Cardiovascular exam was within normal limits revealing only a grade II/VI innocent systolic ejection murmur along the left lower sternal border. Electrocardiogram (ECC) showed evidence for sinus rhythm and Wolff-Parkinson-White syndrome (Fig. 1). Subsequent transtelepbonic monitoring documented the presence of a narrow QRS supraventricular tachycardia (SVT) that was associated with mild shortness of breatb. Craded exercise treadmill test generated a maximum sinus rate of 200 beats/min with persistence of the ventricular preexcitation pattern. No symptoms or SVT developed during exercise testing. Echocardiographic evaluation revealed the suprising finding of a fluid-filled density either within the right ventricular cavity or anterior to the right ventricle, questionably representing a pericardial cyst. Dop-
August 1992
1101
CAMPBELL, ET AL.
Figure 1. Baseline 12-lead ECG demonstrating sinus rhythm with ventricular preexcitation, consistent with a right anterior accessory connection.
pier echocardiography detected no flow within this cavity. There was no displacement of the tricuspid valve to suggest Ebstein's anomaly. The remainder of intracardiac anatomy, function, and Doppler was within normal limits. ECG-magnetic resonance imaging (MRI) likewise demonstrated a fluid-filled density bridging the right AV groove (Fig. 2). There was no displacement of the tricuspid valve. Because of the echocardiographic and MRI findings, the exercise study suggesting short antegrade accessory connection refractory period, and the recurrent clinical episodes of SVT, cardiac catherization and formal electrophysiological study was recommended. During hemodynamic catheterization, normal right heart pressures and saturations were recorded. Right ventricular cineangiogram performed in the anterior-posterior and lateral projection showed a filling defect located along the anterolateral right ventricular horder. Electrophysiological study was consistent with a right anterior accessory connection, with short antegrade (< 170 msec) and retrograde (170 msec) refractory periods. Narrow QRS orthodromic AV reentrant tachycardia (cycle length [CL] = 300 msec) could be repeatedly induced with evidence during SVT for earliest atrial activation along the anterior right
1102
atrium. Nonsustained atrial flutter (atrial CL = 200 msec) with 1:1 accessory connection conduction was associated with profound hypotension. Because of the potentially dangerous electrophysiological properties of the accessory connection, surgical division of the accessory connection was recommended. A median sternotomy was performed; there was no evidence for a pericardial cyst. External inspection of the heart showed separate right and left atrial appendages as well as an anterior hlood-filled mass located between the right atrium and right ventricle. The mass appeared to arise from the anterior right atrium, crossing the right AV groove and connecting to the anterior right ventricular free wall. The color and appearance was that of a normal atrial myocardium. Aspiration of this cavity revealed low pressure venous blood. Intraoperative saline contrast echo performed by way of the internal jugular catheter was inconclusive. Epicardial mapping during right atrial and right ventricular pacing lateralized the functional accessory connection to the anterior right atrium, along the medial aspect of this structure. Cardiopulmonary bypass was instituted, the patient was intentionally fibrillated, and the patent foramen ovale suture closed. Endocardial right atrial mapping was performed during induced
August 1992
PACE, Vol. 15
RIGHT ATRIAL DIVERTICULUM
Dinv HOSPltl C 36-47-18 ix no 5 ll-OCT-W
SI Th
5.8
tlo of ntis 2
n SE 705 Tr.q.del 176 transu Offc An?
LR
-4 V
UU 2328 64 UL ^36 32
Philips 6vroscar)
Figure 2. Tmnsaxial view of right atriai diverticuJum. Spin echo transaxial magnetic resonance image of a three-chambered view o/the heart illuslrafing right afrial diverticulum (dj, traversing (he afrioventricular groove. Right ventricular/ree-vvaJI indentation and a normal tricuspid value are present, a = right atrium; r = right ventricle; I - left ventricJe; and c - coronary sinus. *MRI done on Philips Gyroscan 1.5 Tesla (Philips Medical Systems, Shelton, CT, USAj at Emory University Department of Radiology, Atlanta, Georgia. Cooperative collaboration ivith Roderic 1. Pettigreiv, M.D., Ph.D., Assistant Professor of Hadiology, and W. fames Parks, M.D., Assistant Professor of Pediatrics, Pediatric Cardiologist, Assistant Professor of Radiology.
SVT with evidence for earliest atrial activation along the anterior right atrium, near the medial aspect of the mass. The patient was cooled and cardioplegia administered. At this time, further inspection of the right atrial endocardium detected the orifice of a right atrial diverticulum. Surgical options were discussed. It was felt potentially hazardous to attempt amputation of the right atrial diverticulum, due to possible daniage to the right coronary artery running beneath the diverticulum in the right AV groove. For this reason, an incision was made approximately 2 mm away from the tricuspid valve annulus extending approximately 180° around the tricuspid valve annulus to the right free-wall region. The AV groove fat pad was identified but appeared to be primitive and the dissection was extended
PACE. Vol. 15
out onto the right ventricular free wall for approximately 1 cm until it became apparent that further dissection would result in entry into the diverticulum. Thus the dissection was prevented from extending to the epicardial surface. An additional epicerdial incision was made at the point of the reflection of the fat pad up onto the diverticulum from the right ventricle. There appeared to be no safe way to satisfactorily resect the diverticulum without potential damage to the underlying coronary artery. Accordingly, a series of overlapping cryolesions at -70°G for 90 seconds each were placed throughout the extent of the junction of this diverticulum with the right ventricle in the region of earliest activation. Additional lesions were placed at both ends of the endocardial and epicardial incisions. The incisions were then sutured
August 1992
1103
CAMPBELL, ET AL.
closed and the atrium w^as closed. The patient was weaned from cardiopulmonary bypass and sinus rhythm reestablished with evidence for intact AV conduction, mild first-degree AV block, and no evidence for ventricular preoxcitation. Right ventricular pacing showed no VA conduction. Early postoperative recovery was uneventful, with no evidence for recurrent preexcitation or SVTs. However, within 4 weeks ECG preexcitation returned, matching the preoperative pattern. Follow-up electrophysiological evaluation revealed inducible orthodromic AV tachycardia with CL 290 msec, using a right anterior accessory connection as the retrograde limb. The accessory connection ERP was < 240 msec antegrade and < 230 msec retrograde. Induced atrial fibrillation resulted in hypotension with a short preexcited RR interval of 210 msec. A second attempt at operative repair was recommended to the family; at this time, they have opted for no further surgical intervention.
Discussion This report deals with a rare congenital right atrial diverticulum that crossed the right AV groove and functioned as an accessory connection supporting Wolff-Parkinson-White preexcitation and its associated tachycardias. True atrial diverticulum is a rarely reported lesion, which must be differentiated from symmetrical dilatation of the atrium. Diverticula have heen noted from the right and left atria.^^^ Morrow and Behrendt^ reported a congenital right atrial aneurysm associated with
recurrent tachycardia and significant decrease in cardiac output in a 23-year-old female. The ECG mechanism of the tachycardias was atrial flutter and atrial fibrillation. Normal sinus rhythm resumed immediately following amputation of the diverticulum. To our knowledge, the association between right atrial diverticulum and the Wolff-ParkinsonWhite syndrome has not been reported. Lack of histologic evaluation in this case does not allow us to differentiate between a direct myocardial connection or the presence of a true accessory connection. The etiology of this patient's diverticulum is unclear; however, this case must represent more than just a simple outpouching from the right atrium, due to the obvious direct electrical connection to the anterior right ventricle. Congenital ventricular diverticula presenting with premature ventricular complexes, accelerated idioventricular rhythm, and ventricular tachycardia have been reported both the right and left ventricles.''•^ Pathologically, these diverticula are classified as either fibrous or muscular. In terms of etiology, these lesions may result from congenital pericardial cysts or a weakness in the ventricular muscle. This represents the first description of an atrial diverticulnm using MRI techniques. Because of the anterior substernal position of this diverticulum, echocardiographic evaluation was never completely definitive. MRI suggested that the diverticulum crossed the AV groove, offering the first clue that this undefined lesion perhaps contributed to the patient's electrical pattern of preexcitation.
References 1. Petit A, Eicher JC, Louis P. Congenital diverticulum of the right atrium situated on the floor of the coronary sinus. Br Heart } 1988; 59:721723. 2. Pitts RM. Potts WJ. Congenital diverticulum of the left atrium. Arch Surg 1962; 84:82-84. 3. Morrow AG, Behrendt DM. Congenital aneurysm (diverticulum) of the right atrium; clinical manifes-
1104
August 1992
tations and results of operative treatment. Circulation 1968; 38:124-128. Shen EN, Fukuyama O, Herre JM, et al. Ventricular tachycardia with congenital ventricular diverticulum. Chest 1991; 100(l):283-285. Hamaoka K, Sawada T. Isolated congenital right ventricular diverticulum with ventricular premature complexes. Am ] Cardiol 1988; 61(6):480-481.
PACE, Vol. 15
