Transient neonatal tricuspid regurgitation: a Doppler echocardiographic study of three cases.

Three patients with normal hearts and no pulmonary abnormality had neonatal tricuspid regurgitation causing cardiorespiratory distress and cyanosis. The signs of tricuspid regurgitation resolved over a few weeks. In the acute phase echocardiography showed gross dilatation of the right atrium and ventricle. The interatrial septum bulged into the left atrium during the whole cardiac cycle. Doppler echocardiography showed clinically significant tricuspid regurgitation, a right to left shunt through the foramen ovale, reduced flow through the pulmonary valve, and in two patients ductal flow into the pulmonary artery. In one patient tricuspid regurgitation was so great that it impeded the opening of the pulmonary valve and produced functional "atresia" of the pulmonary valve. The presence of regurgitant blood flow through the pulmonary valve showed that the "atresia" was functional rather than organic. Doppler echocardiographic study is useful in distinguishing functional neonatal tricuspid regurgitation from structural abnormality of the tricuspid valve.     

Transient neonatal tricuspid regurgitation: a Doppler echocardiographic study of three cases

Three patients with normal hearts and no pulmonary abnormality had neonatal tricuspid regurgitation causing cardiorespiratory distress and cyanosis. The signs of tricuspid regurgitation resolved over a few weeks. In the acute phase echocardiography showed gross dilatation of the right atrium and ventricle. The interatrial septum bulged into the left atrium during the whole cardiac cycle. Doppler echocardiography showed clinically significant tricuspid regurgitation, a right to left shunt through the foramen ovale, reduced flow through the pulmonary valve, and in two patients ductal flow into the pulmonary artery. In one patient tricuspid regurgitation was so great that it impeded the opening of the pulmonary valve and produced functional "atresia" of the pulmonary valve. The presence of regurgitant blood flow through the pulmonary valve showed that the "atresia" was functional rather than organic. Doppler echocardiographic study is useful in distinguishing functional neonatal tricuspid regurgitation from structural abnormality of the tricuspid valve.     

Valve-incompetent foramen ovale in premature infants with ductus arteriosus: a Doppler echocardiographic study

In a 1 year period, 56 neonates with a clinical diagnosis of ductus arteriosus had Doppler echocardiographic confirmation of the ductus; 33 (59%) had additional, turbulent left to right flow at the atrial level through a valve-incompetent foramen ovale. Normalized left atrial dimensions in the group with the atrial shunt were significantly larger than when there was a competent foramen ovale; when the ductus closed and left atrial enlargement receded, the atrial shunt disappeared. However, several infants with large left chambers had no interatrial shunting. When the atrial shunt was present, there were up to three flow pulses, corresponding to atrial systole, ventricular systole and ventricular diastole, but these were frequently fused into two pulses or even one pulse per cycle. The atrial septal morphology provided supporting clues: general bowing of the septum or a localized bulge in the region of the foramen ovale indicated relatively high left atrial pressure, and frequently a slitlike dropout could be seen at the superior edge of the foramen. During the study, three additional neonates with a ductus arteriosus were found to have a secundum atrial septal defect with a typical echographic image, "matchhead" appearance of the septal rim of the defect, but the Doppler flow patterns were indistinguishable from those of a valve-incompetent foramen ovale. The hemodynamic effects of the interatrial shunt, from either cause, seemed slight during the hospital course, but the presence of a valve-incompetent foramen ovale indicated a relatively large ductal shunt. Quantification of the ductal shunt, however, continues to rely primarily on measurement of the left atrial and ventricular size.     

Acquired cyanotic heart disease secondary to traumatic tricuspid regurgitation: Case report with a review of the literature

A case of traumatic tricuspid insufficiency leading to right atrial enlargement and to a patent foramen ovale with right to left shunting is presented. Six similar cases previously reported are reviewed. The time course of clinical deterioration was related to the type of tricuspid valve damage incurred. Papillary muscle rupture led to surgery within a year, whereas less severe chordal damage allowed a more benign course that lasted from 10 to 25 years from the time of injury to the time of surgery. Surgical repair of the incompetent tricuspid valve and closure of the atrial septal defect led to significant improvement. The diagnostic usefulness of radionuclide imaging and echocardiography is demonstrated in this case.

A mechanism of right to left interatrial shunting in the presence of normal pulmonary arterial pressures is proposed; this invokes phasic increases in right atrial pressure from tricuspid insufficiency and streaming of blood from the inferior vena cava into the left atrium across a patent foramen ovale in a manner that resembles conditions in the fetal circulation.     

Tricuspid regurgitation causing a right to left interatrial shunt with normal pulmonary pressures

We describe a patient who presented with asymptomatic hypoxia refractory to supplemental oxygen. Transthoracic echocardiography and angiography demonstrated a tricuspid valve with a large regurgitant jet oriented directly at a patent foramen ovale, producing a right to left shunt with systemic hypoxia. The patient was found to have normal right-sided cardiac pressures as well as normal pulmonary arterial pressures, demonstrating the shunt was secondary to the tricuspid regurgitant jet and not a result of a pressure gradient between atria. Surgical correction of the tricuspid valve and closure of the patent foramen ovale resulted in resolution of the patient's hypoxemia.     

Alternate pathways to pulmonary venous flow in left-sided obstructive anomalies.

In cardiac anomalies causing severe obstruction in the left side of the heart, such as aortic atresia, mitral atresia, or occasionally severe aortic stenosis, maintenance of circulation depends upon shunting of pulmonary venous blood into the right atrium. The usual pathway by which the shunt is achieved is across the atrial septum through the foramen ovale. When this route is closed or severely narrowed, alternate but less common pathways may exist. These involve either anomalous connections of pulmonary veins to systemic veins or communications with the coronary venous system. In the latter, as commonly occurs in aortic atresia, left ventricular myocardial sinusoids carry pulmonary venous blood from the left ventricular cavity and into the cardiac veins. In other instances of severe left-sided obstruction, a direct communication may exist between the left atrium and the coronary sinus.     

Profound hypoxaemia corrected by PFO closure device in carcinoid heart disease.

A 66-year-old man with known metastatic carcinoid tumor presented with increasing dyspnoea, right heart failure and marked hypoxaemia which did not correct with oxygen. Echocardiography demonstrated severe tricuspid regurgitation, moderate pulmonary regurgitation and marked right heart dilatation. The inter-atrial septum was aneurysmal, with a large patent foramen ovale (PFO) with continuous right to left shunting. Cardiac catheterization demonstrated oxygen saturations of 96% in the pulmonary veins and 74% in the left atrium with a significant right to left shunt. During percutaneous closure of the PFO, anaesthetic induction resulted in marked systemic hypotension and worsening hypoxia related to systemic vasodilatation and increased shunting. PFO flow was temporarily obstructed with a sizing balloon resulting in a rapid increase in arterial oxygen saturation from 60% to >90%, but marked systemic hypotension due to acute left ventricular preload reduction, requiring volume replacement and adrenaline. Following deployment of a PFO occluder device, prominent pulsatile splaying of the right and left discs was noted due to the severe tricuspid regurgitation, resulting in some residual inter-atrial shunting. Arterial oxygen saturation was 83%, increasing to 92% at day 4 post-procedure as tissue organization occurred within the device, and the patient reported improvement in dyspnoea.     

Chronic tricuspid regurgitation and bifascicular block due to blunt chest trauma

Closed-chest trauma in a young man was followed by rupture of a right ventricular papillary muscle and bifascicular block. This produced signs and symptoms of tricuspid regurgitation and recurrent syncope. Treatment by valve replacement and pacemaker implantation was successful. Review of 30 cases of traumatic tricuspid regurgitation reveals that this patient had characteristic findings: adult onset of isolated tricuspid regurgitation, a history of trauma, right bundle branch block, and cardiomegaly without signs of left ventricular failure. In addition, right atrial hypertension of longstanding may produce cyanosis because of right-left shunting through a patent foramen ovale.     

Reversible platypnoea and orthodeoxia after surgical removal of an hydatid cyst from the liver.

A patient with a large hydatid cyst of the liver developed a positionally symptomatic right to left shunting across a patent foramen ovale with both platypnoea and orthodeoxia, despite normal pulmonary arterial pressures and normal pulmonary function tests. When the patient was in the supine position the calculated right to left shunt was 15.1% and 29.5% when seated. The shunt was attributed to the compression of the right atrium and ventricle by the cyst. Surgical evacuation of the cyst relieved the symptoms and the positionally induced shunting.     

Patent foramen ovale and hypoxaemia with or without elevated right heart pressures

The prevalence of patent foramen ovale (PFO) is high. As identified at autopsy it is found in approximately 25% of the general population. Anatomically a PFO represents a channel through which unidirectional blood flow from the right to the left atrium may occur. This potential interatrial shunt of unoxygenated venous blood into the oxygenated arterial system may lead to hypoxaemia. Usually right to left shunting across a PFO is transient and without clinical significance. Increased pulmonary arterial pressure may give rise to left-right pressure gradient reversal and right to left shunting across a PFO. High pressure in the right heart chambers, even without pulmonary arterial hypertension, can potentially lead to the reopening of a foramen ovale. In other cases inferior vena cava flow deviation might lead to right to left shunting across a PFO. Right to left shunting without pressure increase inside the right heart chambers is usually transient and even positional and its diagnosis is more difficult.     

LEFT HEART INVOLVEMENT WITH CARDIAC SHUNT COMPLICATING CARCINOID HEART DISEASE

The manifestations of carcinoid heart disease are usually right heart failure due to pulmonary and tricuspid valve disease and sometimes high output failure due to peripheral vasodilation. Recently there has been one case report of progressive central cyanosis due to right to left shunting through a patent foramen ovale.¹ We present a similar case where such a shunt developed and was also complicated by significant valvular disease affecting the left side of the heart.     

Left-to-right shunt via the foramen ovale in the early neonatal period: evaluation by Doppler color flow mapping

Serial two-dimensional Doppler echocardiography was performed in 22 normal neonates (2-9 hours after birth). A left-to-right shunt through the foramen ovale and a shunt through the ductus arteriosus were evaluated. Interatrial shunts were observed as transseptal jets in 16 of 22 neonates on initial examination and resolved nine to 26 hours after birth in 13 neonates. In the remaining three neonates the shunts were observed more than six days and resolved by two months of age. Shunts through the ductus arteriosus were observed in all neonates examined as diastolic or continuous flows toward the transducer in the main pulmonary artery at the initial examination. The ductal flow resolved simultaneously with (3/13) or after (10/13) the disappearance of interatrial flow. With two-dimensional echocardiography, the enlarged left atrium and rightward deviation of the interatrial septum were observed in the neonates with interatrial shunts. This was confirmed by the immobile septum primum and the increased ratio of the left atrial to aortic diameters (LA/Ao ratio) on the M-mode echo. The interatrial septum became mobile and the LA/Ao ratio decreased after disappearance of the interatrial shunts. It was speculated that in neonates with large ductal shunts, large pulmonary venous flow enters into the less compliant left ventricle and raises the left ventricular end-diastolic pressure. Then, increased left atrial pressure distends the interatrial septum and causes left-to-right interatrial shunts via the stretched foramen ovale. This shunt is considered one of the physiological phenomena occurring in the early neonatal period.     

An echocardiographic study of perimembranous ventricular septal defect with left ventricular to right atrial shunting

Twenty nine patients with isolated perimembranous ventricular septal defects were investigated by M mode, cross sectional, and pulsed Doppler echocardiography. Tricuspid valve anomalies were present in all six patients with a left ventricular-right atrial shunt but in only six (26%) of 23 patients who had interventricular shunts only. Systolic flutter of the tricuspid valve was shown in five (83%) of the six patients with a ventriculoatrial shunt but not in the other patients. Systolic turbulence in both the right ventricle and right atrium was detected by Doppler echocardiography only in patients with ventriculoatrial shunting. A perimembranous ventricular septal defect with left ventricular to right atrial shunt can be diagnosed by its combined M mode, cross sectional, and pulsed Doppler echocardiographic features.     

An echocardiographic study of perimembranous ventricular septal defect with left ventricular to right atrial shunting.

Twenty nine patients with isolated perimembranous ventricular septal defects were investigated by M mode, cross sectional, and pulsed Doppler echocardiography. Tricuspid valve anomalies were present in all six patients with a left ventricular-right atrial shunt but in only six (26%) of 23 patients who had interventricular shunts only. Systolic flutter of the tricuspid valve was shown in five (83%) of the six patients with a ventriculoatrial shunt but not in the other patients. Systolic turbulence in both the right ventricle and right atrium was detected by Doppler echocardiography only in patients with ventriculoatrial shunting. A perimembranous ventricular septal defect with left ventricular to right atrial shunt can be diagnosed by its combined M mode, cross sectional, and pulsed Doppler echocardiographic features.     

Orthodeoxia platypnea syndrome in a patient with lipomatous hypertrophy of the interatrial septum due to long-term steroid use

We describe an unusual case of orthodeoxia platypnea syndrome exacerbated by right ventricular inflow obstruction due to iatrogenic steroid-induced adipose deposition in cardiac tissues. A 68-year-old man on long-term prednisone therapy for eosinophilic pneumonia presented with progressive dyspnea worsened by bending forward. By using pulse oximetry, he was noted to have positional hypoxemia. Transthoracic echocardiogram demonstrated normal right-sided pressures but severe right to left shunting through a patent foramen ovale. Transesophageal echocardiogram showed a large patent foramen ovale, severe lipomatous hypertrophy of the interatrial septum, and massive adipose deposition in the pericardium causing compression of the right ventricular inflow tract. The patient underwent percutaneous closure of the patent foramen ovale, which resulted in the resolution of symptoms and hypoxemia. This case is unique because long-term steroid use resulted in reverse Lutembacher physiology and clinical orthodeoxia platypnea syndrome by inducing lipomatous hypertrophy of the interatrial septum and compression of the right atrium.     

Cor triatriatum dexter. Persistent right sinus venosus valve

The usual causes of a large right to left shunt at the atrial level are tricuspid or pulmonary atresia, severe pulmonary stenosis, Ebstein's anomaly or a large atrial septal defect with pulmonary hypertension. We have recently evaluated a patient with a large right atrial membrane which subdivided the right atrium into 2 chambers with the venae cavae and foramen ovale on one side of the web and the coronary sinus and a small tricuspid valve on the other. The presence of this membrane was demonstrated preoperatively by cineangiograms, and it was successfully removed at operation. This unusual entity, cor triatriatum dexter, is discussed and the literature reviewed.     

Patent foramen ovale associated with platypnea and orthodeoxia

A case of positionally symptomatic right-to-left shunting across a patent foramen ovale with both platypnea and orthodeoxia despite normal pulmonary arterial pressures and normal right ventricular function is documented. When the patient was in a supine position, the calculated right-to-left shunt was 12.8 percent, and when seated 25 percent. Surgical closure of the patent foramen ovale relieved the symptoms and positionally induced shunting. The prevalence and associations of permanent and intermittent patency of the foramen ovale are discussed. It is recommended that those at risk of thromboembolism be screened for patency by contrast ultrasound or color flow techniques. If present, surgical closure needs to be considered to prevent paradoximal embolism and stroke.     

A rare cause of mitral insufficiency: left atrial anomalous band

Anomalous muscular bands have been seen in the left ventricle and right and left atria. Although the significance of left ventricular false tendons and right atrial anomalous muscular bands have been reported previously, the importance of anomalous muscular bands observed in the left atrium is not clearly defined. They have been found to be associated with Chiari's network, patent foramen ovale, and supraventricular arrhythmias. We describe a left atrial anomalous band causing mitral valve prolapse and mitral regurgitation.     

Morphological aspects of Ebstein's anomaly in adults

The essence of the Ebstein's malformation is that the tricuspid valve leaflets do not attach normally to the valve annulus, and the effective orifice is displaced downward into the right ventricular cavity at the junction of the inlet and trabecular components of the right ventricle. Only the septal and posterior leaflets are displaced and divide the right ventricle into two portions. The inlet portion is usually integrated functionally with the right atrium ("atrialized portion"), while the other, including the trabecular and outlet portions, constitutes the functional right ventricle. The proximal atrialized right ventricle often has a wall thinner than the distal functional right ventricle, due to partial congenital absence of myocardium. An atrial septal defect is present in more than one-third of hearts, and the majority of the remainder has a patent foramen ovale resulting in a right-to-left shunt. The downward displacement of the septal tricuspid valve leaflet is associated with discontinuity of the central fibrous body and septal atrioventricular ring, thus creating a potential substrate for accessory atrioventricular connections and ventricular pre-excitation making the patient at risk of sudden death. Angiography has demonstrated that a significant number of patients with Ebstein's anomaly also have morphofunctional abnormalities of the left ventricle, which may be explained by increased fibrosis in the left ventricular wall and ventricular septum as demonstrated by histological studies. Regarding embryology, the leaflets and tensile apparatus of the tricuspid valve are believed to be formed mostly by a process of delamination of the inner layers of the inlet zone of the right ventricle. The downward displacement of the leaflets in Ebstein's anomaly suggests that delamination from the inlet portion failed to occur.