Pulmonary Branches Research Articles

Severe Left Main Coronary Artery Stenosis with Abnormal Branching Pattern in a Patient with Mild Supravalvar Aortic Stenosis and Williams-Beuren Syndrome

Williams-Beuren syndrome (WBS) is a multisystem genetic disorder comprising of craniofacial, developmental, and cardiac malformations. The most common cardiac defects found are supravalvar aortic stenosis and peripheral pulmonary stenosis. However, WBS should be regarded as a general arteriopathy consisting of stenoses of medium- and large-sized arteries including the coronary arteries. Cardiac manifestations are often the initial reason for referral and careful cardiovascular assessment is important as coronary artery involvement confers a significant anesthetic risk and may be associated with ischemia and resultant ventricular dysfunction. Here we review the literature and describe a 2-year-old boy with evolving clinical features of WBS. He presented to our pediatric cardiology department for a routine assessment of peripheral pulmonary branch stenosis. A 12-lead electrocardiogram showed changes consistent with left ventricular ischemia and a two-dimensional echocardiogram showed reduced left ventricular function and mild supravalvar aortic stenosis. Subsequent cardiac catheterization diagnosed severe left main coronary artery stenosis. Deteriorating ventricular function secondary to acute ischemia postcatheterization required intensive care treatment from which the patient did not recover. This case report highlights the necessity of careful cardiology assessment without delay in patients with a suspicion of WBS. Isolated coronary stenosis though rare in WBS should be considered in the presence of ischemia or reduced ventricular function. Larger case series are needed to further characterize the correlation between WBS and acute coronary events.

Pulmonary regurgitation and pulmonary branch kinking: long-term complication in adults with repaired tetrallogy of Fallot

Cardiologia CROATICA The major long-term complication of tetralogy of Fallot repair is pulmonary valve insufficiency, which leads to right heart failure. Other problems include atrial and ventricular arrhythmias and sudden cardiac death. We report a case of progressive pulmonary valve regurgitation late after tetralogy of Fallot correction. A 26-year old woman with history of Ductus Botalli closure and complete tetralogy of Fallot correction at the age of two, was evaluated for palpitation, intermittent leg edema, progressive exertion intolerance New York Heart Association (NYHA) functional class II/III and a syncope episode. On examination, sinus rhythm and a systolic and early diastolic murmur was noted at the high left sternal border and at the back. Electrocardiography shows right ventricular (RV) hypertrophy with a right bundle branch block. First transthoracic echocardiogram (TTE) showed right ventricle hypertrophy (Figure 1) and mild pulmonary valve regurgitation. The presence of Doppler flow turbulence and increased velocity jet in the left branch pulmonary artery was suggesting the stenosis. Magnetic resonance imaging (MRI) also showed right ventricular hypertrophy, mild pulmonary regurgitation and narrowing of the main pulmonary artery at branching (diameter 12 mm / 20 mm) suggesting mild stenosis. Cardiac catheterization confirmed the diagnosis of anomal coronary artery origin, all from the right coronary sinus. Left pulmonary artery stenosis with pressure gradient less than 20 mmHg was detected on right pulmonary angiography. A computed tomographic scan of thorax was further arranged to delineate the pulmonary artery anatomy; this confirmed mild left branch pulmonary artery narrowing. Perfusion lung scan ratio was 65% right to 35% left. In 6 months follow-up, progressive dyspnea and exercise intolerance occurred. Control TTE revealed significant impairment of pulmonary regurgitation (Figure 2). Stress TTE confirmed increase in pulmonary regurgitation while significant pulmonary transvalvular and peripheral pulmonary gradient remained the same. Patient was scheduled for surgery. At operation, the main left pulmonary artery was found to be kinked with adhesions. The annulus of the pulmonary valve was dilated and one of the cusps was completely destructed. Left pulmonary artery unkinking and pulmonary bioprosthetic valve replacement was done. Soon after operation the patient made an uneventful recovery. At her 6-month follow-up, she remains in NYHA functional class I with no symptoms, follow-up TTE revealed reversal remodeling of the RV, normal bioprosthetic function, transpulmonary and peripheral flow. Proπireni saaeetak / Extended abstract

CCR2 Deficiency, Dysregulation of Notch Signaling, and Spontaneous Pulmonary Arterial Hypertension

In pulmonary arterial hypertension (PAH), there is overexpression of the chemokine, C-C chemokine ligand type 2 (CCL2), and infiltration of myeloid cells into the pulmonary vasculature. Inhibition of CCL2 in animals decreases PAH, suggesting that the CCL2 receptor (CCR2) plays a role in PAH development. To test this hypothesis, we exposed wild-type (WT) and CCR2-deficient (Ccr2(-/-)) mice to chronic hypobaric hypoxia to induce PAH. After hypoxic stress, Ccr2(-/-) mice displayed a more severe PAH phenotype, as demonstrated by increased right ventricular (RV) systolic pressures, RV hypertrophy, and tachycardia relative to WT mice. However, these mice also exhibited increased RV systolic pressures and increased pulmonary artery muscularization under normoxic conditions. Moreover, Ccr2(-/-) mice displayed decreased pulmonary vascular branching at 3 weeks of age and increased vascular muscularization at birth, suggesting that an abnormality in pulmonary vascular development leads to spontaneous PAH in these animals. No significant differences in cytokine responses were observed between WT and Ccr2(-/-) mice during either normoxia or hypoxia. However, Ccr2(-/-) mice displayed increased Notch-3 signaling and dysregulated Notch ligand expression, suggesting a possible cause for their abnormal pulmonary vascular development. Our findings imply that CCR2 does not directly contribute to the development of PAH, but does play a previously unrecognized role in pulmonary vasculature development and remodeling wherein the absence of CCR2 results in spontaneous PAH, most likely via dysregulation of Notch signaling. Our results demonstrate that CCR2 has impacts beyond leukocyte recruitment, and is required for the proper expression of Notch signaling molecules.

Developmental expression and transcriptional regulation of claudin‐6 in the murine lung

Claudins contribute to tight junctions that prevent paracellular transport of extracellular fluid and diverse substances. Claudin‐6 was evaluated by qPCR and immunohistochemistry and its expression was confirmed to peak at E12.5 and diminish as development progressed. Co‐immunofluorescence revealed that Claudin‐6 co‐localized with Sox2 and Sox9, both factors that influence cell differentiation in the proximal and distal lung, respectively. Claudin‐6 was also detected in cells that express TTF‐1, a critical regulator of pulmonary branching morphogenesis. In order to assess transcriptional control of Claudin‐6, its promoter was ligated into a luciferase reporter vector and co‐transfected with TTF‐1 and other important transcriptional regulators. Factor‐specific effects were confirmed using site‐directed mutagenesis of putative response elements located in the Claudin‐6 promoter. This work revealed for the first time that Claudin‐6 might be an important tight junctional component during lung organogenesis. Furthermore, these and other data may reveal important Claudin‐6‐ mediated aspects of lung cell metastasis, remodeling, and disease states coincident with abnormal membrane permeability. This work was supported by a grant from the Flight Attendant's Medical Research Institute (FAMRI, PRR) and a BYU Mentoring Environment Grant (PRR).

Pulmonary and intracardiac cement embolism after a percutaneous vertebroplasty

A 68-year-old woman was admitted to our hospital complaining of dyspnoea and chest pain. She had neither prior cardiac history nor any other relevant medical history except from osteoporosis and Parkinson disease. She underwent percutaneous vertebroplasty for fusion of L1-S1 and fracture of L3, 2 months ago in another institution. Arthrodesis L1-S1 and laminectomy of L3 was successfully performed and she was discharged home 2 weeks later. She referred having started with chest pain and dyspnoea 2 weeks ago. On examination, she was haemodynamically stable, her blood pressure was 112/70 mmHg and her heart rate 75 bpm. Her room air oxygen saturation was 95 %. Cardiopulmonary auscultation was normal. ECG showed no relevant findings and the chest radiography only highlighted lumbar arthrodesis. A transthoracic echocardiography was performed as a first approach, followed by a transesophageal echocardiogram (Fig. 1). We found a normal ventricular ejection function of both ventricles and surprisingly we discovered a calcium density foreign body in the right atrium located in the septum, next to the the fossa ovalis. An exhaustive clinical history and physical examination were performed to rule out the possibility of a paradoxical embolism. Afterwards, a chest computed tomographic (CT) scan (Fig. 2) was performed, which confirmed the existence of several fragments of blade material, one of them, with a linear morphology, was crossing the atrial septum, located mostly in the left atrium. There were two other fragments, one located in the left lower lobe artery, at about 3.5 cm of the origin of the left main artery and the other in a subsegmental branch of the left basal segments. In this clinical context, these fragments were compatible with vertebroplasty cement fragments, which protruded into the left atrium and into the pulmonary branches. Given these findings, we decided to perform surgery. Under general anesthesia through a median sternotomy and normothermic cardiopulmonary bypass, opening of the right atrium was performed, with removal of the foreign body and closure of the oval foramen. We also carried out longitudinal opening of the left pulmonary artery from the bifurcation to the beginning of the lobar arteries, extracting the foreign body from the left lower lobe artery (Fig. 3). The patient did well and could be discharged 10 days after the surgery. Percutaneous vertebral minimally invasive procedures are becoming the standard treatment for osteoporotic vertebral fractures and osteolytic vertebral tumors (metastasis, myeloma and hemangioma) [1]. These techniques include vertebroplasty, kyphoplasty and skyphoplasty. In all of them, an injection of polymethylmethacrylate into the vertebral body is performed under fluoroscopy or computed tomographic scan guidance. In the kyphoplasty, an inflatable balloon is used to create a cavity in the vertebral body that will be filled with the cement, and a plastic tube is used in the skyphoplasty. Percutaneous vertebroplasty was the first procedure described and has been shown to improve symptoms and quality of life of patients with vertebral compression fractures [2]. The procedure requires the R. A. Llanos (&) A. Viana-Tejedor F. Fernandez-Aviles Cardiology Department, Hospital General Universitario Gregorio Maranon, Doctor Esquerdo St, 46, 28007 Madrid, Spain e-mail: rocioang1@hotmail.com

Non-ECG-gated MDCTA of infracardiac total anomalous pulmonary venous connection in neonates and young infants

To compare the diagnostic accuracy of non-electrocardiogram-gated (non-ECG-gated) multidetector computed tomography angiography (MDCTA) with transthoracic echocardiography (TTE) in the evaluation of infracardiac total anomalous pulmonary venous connection (TAPVC) in neonate and infant patients. Nine patients aged from 2days to 3months were included in this study. All clinical and imaging data were reviewed. Compared with findings from surgery, the diagnostic accuracy of MDCTA and TTE was calculated in three respects: the path of the drainage vein, the drainage site, and the stenosis of the vein. Images acquired from all patients were eligible for diagnosis and reconstruction. The sites of the drainage point were all clarified and the drainage vessels were oriented by axial and reconstructed images. Stenosis was found at 13 sites, including mild stenosis at the diaphragmatic level (n = 3), distortion or stenosis at the drainage site (n = 5), and hypogenesis of the pulmonary vein branch (n = 5). TTE misdiagnosed the upward-flowing collateral vessels as the drainage veins in 2patients and misidentified the drainage site in 7patients, yielding an accuracy of 77.8% and 22.9%, respectively. It identified stenosis at four sites at the drainage site in concordance with MDCTA. The hypogenesis of the pulmonary vein branch was not detected and the stenosis at the diaphragmatic level was not suggested by TTE. For infracardiac TAPVC, non-ECG-gated MDCTA is superior to TTE and can facilitate the preoperative evaluation when combined with TTE.

Letter to the Editor Unexpected cause of syncope in a young woman

Letter to the Editor Unexpected cause of syncope in a young woman

A Case Report of Iatrogenic Pulmonary Artery Injury due to Chest-Tube Insertion Repaired under Cardiopulmonary Bypass

The authors presented a case of a 50-year-old patient with multiple trauma who suffered from the inadvertent cannulation of the main pulmonary artery at the second attempt of left chest drainage. Pulmonary artery injury has been suspected because early chest tube production was 2300 mL of blood. CT scan showed injury of the trunk of the pulmonary artery, left hemothorax, and suspect damage of the right branch of the pulmonary artery. That chest tube touched the posterior wall of ascending aorta. Surgical approach was median sternotomy. Exploration showed a perforation of the trunk of pulmonary artery without lesion of the right pulmonary branch and the posterior wall of the ascending aorta. The lesion was repaired under normothermic partial cardiopulmonary bypass. Postoperative period was free of events. Review of the literatures for this rare case report has been done.

A Perfect Match Condition for Point-Set Matching Problems Using the Optimal Mass Transport Approach

We study the performance of optimal mass transport-based methods applied to point-set matching problems. The present study, which is based on the L2 mass transport cost, states that perfect matches always occur when the product of the point-set cardinality and the norm of the curl of the non-rigid deformation field does not exceed some constant. This analytic result is justified by a numerical study of matching two sets of pulmonary vascular tree branch points whose displacement is caused by the lung volume changes in the same human subject. The nearly perfect match performance verifies the effectiveness of this mass transport-based approach.

Type II Congenital Pulmonary Airway Malformation in an Esophageal Lung

A seven-month-old girl, born prematurely (birth weight 1000 g) from a twin pregnancy, was admitted to hospital due to recurrent pneumonia and atelectasis. She experienced cough and respiratory distress during feeding. The right hemithorax was smaller than the left, with diminished breath sounds and dullness. Chest x-rays revealed decreased lung volume and multiple radiolucent images in the right lung, as well as overdistention of the left lung. An esophagogram revealed three bronchial branches arising from the lower one-third of the esophagus, corresponding to the right lung and ending in a cul-de-sac. A diagnosis of esophageal lung was established. On bronchography, the right lung was absent and the trachea only continued into the left main bronchus. Echocardiography and angiotomography revealed agenesis of the pulmonary artery right branch. The surgical finding was an esophageal right lung, which was removed; the histopathological diagnosis was type II congenital pulmonary airway malformation in an esophageal lung.

Thoracoscopic Lung Segmentectomy Simulated by a Tailor-Made Virtual Lung: Computed Bronchography and Angiography

We describe the benefits of simulating an anatomical lung segmentectomy using multidetector computed tomography bronchography and angiography (tailor-made virtual lung). Preoperative determination of the anatomical intersegmental plane is possible by visualizing the segmental bronchi and pulmonary vein branches. This advanced technique could be useful during thoracoscopic anatomical segmentectomy for lung cancer.

Pulmonary vein morphology by free‐breathing whole heart magnetic resonance imaging at 3 tesla versus breathhold multi‐detector computed tomography

To compare pulmonary vein and left atrial anatomy using three-dimensional free-breathing whole-heart magnetic resonance imaging (MR) at 3 Tesla (T) and multi-detector computed tomography (MDCT). Thirty-three subjects (19 male, age 49 ± 12 years) underwent free-breathing 3T MR and contrast-enhanced MDCT during inspiratory breath hold. Pulmonary vein parameters (ostial areas, diameters, angles) were measured. All pulmonary veins and anomalies were identified by 3T MR and by MDCT. The right-sided pulmonary veins were directed more posteriorly, the right superior pulmonary vein more inferiorly, and the right inferior pulmonary vein more superiorly by 3T MR when compared with MDCT. The cross-sectional area, perimeters and minimum diameters of right-sided pulmonary vein ostia were significantly larger by MR, as were the maximum diameters of right and left inferior pulmonary veins. There were no significant differences between techniques in distance to first pulmonary vein branch. Pulmonary vein measurements demonstrated significant differences in angulations and dimensions when 3T MR is compared with MDCT. These differences likely represent hemodynamic and respiratory variation during free-breathing with MR versus breath-holding with MDCT. MR imaging at 3T during free-breathing offers an alternate method to define pulmonary vein and left atrial anatomy without exposure to radiation.

Aortopulmonary Window With Pulmonary Atresia: A Very Rare Association

Aortopulmonary window (APW) is a rare congenital cardiac malformation accounting for 0.1–0.2 % of all cardiac defects in live births [1]. When APW is combined with other cardiac malformations, diagnosis is a challenge [1]. A 27-day-old, full-term child with a birth weight of 2.3 kg, which is small for gestation age, presented on day 15 of life with history of feeding difficulty and features of congestive heart failure. The oxygen saturation was 90 %, and the child was tachypnic. The findings showed respiratory rates of 70 breaths/min with minimal retractions, tachycardia with heart rates of 160 beats/min, and significant hepatomegaly. There were no signs of extracardiac malformations. Echocardiography showed valvular pulmonary atresia, confluent and adequate-sized branch pulmonary arteries, right and left pulmonary arteries each 4.5 mm in size (expected size, 4 mm), nonrestricted perimembranous ventricular septal defect (VSD) extending to the outlet muscular septum, bidirectional shunting, and a 5 mm fossa ovalis atrial septal defect with left-to-right shunting. The child had aortic override exceeding 50 %. The aortic arch was right sided with flow reversal in the arch. There was a large distal type anteroposterior window with laminar flow (Figs. 1, 2, 3). The differential diagnosis of a common arterial trunk type 1 could be ruled out as atretic pulmonary valve was clearly seen. Due to progressive signs of congestive heart failure despite adequate medical treatment, surgical correction was indicated and performed successfully. The findings were confirmed intraoperatively. In the setting of APW, pulmonary atresia remains a diagnostic challenge because the echocardiographic imaging of pulmonary atresia does not correspond to the clinical features of increased pulmonary blood flow. This particular setting should alert the clinician to investigate for an associated lesion such as APW. A case of APW in a fetus, with detection of pulmonary atresia, also has been reported. A diagnosis of APW associated with tetralogy of Fallot has been reported in 22 cases to date, seven of which had pulmonary atresia [2–5]. Most reported cases of isolated or combined forms of APW have been treated with surgery in infancy or later childhood. Therefore, early surgical intervention for complex lesions such as APW with additional intracardiac defects can be performed successfully in one step.

Surgical repair of truncus arteriosus in children: early results and long-term outcomes

To recite early results and long-term outcomes after surgical repair of persistent truncus arteriosus (PTA). The clinic data of 54 patients underwent surgical repair for PTA from January 1999 to December 2009 was analyzed retrospectively. There were 36 male and 18 female patients, with a mean age of (9 ± 10) months (range, 1 to 38 months; median, 5 months). Preoperative mechanical ventilation was required in 5 patients. The surgical procedures were closure of ventricular septal defect and re-establishment of continuity between right ventricle and pulmonary artery. The right ventricular outflow tract (RVOT) was reconstructed by direct anastomosis pulmonary artery to right ventriculotomy with anterior wall patch enlargement (28 cases), or by inserting conduits (26 cases). Valvuloplasty were performed in 4 patients with truncal valves moderate to severe insufficiency and aortoplasty in 3 patients with interrupted aortic arch (IAA). There were 3 patients (5.6%) died of pulmonary hypertensive crisis in hospital. The mean duration of ventilation was 6.8 days in 5 patients who were intubated before operation, while the others were 3.6 days. Forty-seven (92.2%) patients were followed-up for mean (6.8 ± 2.5) years (from 2.5 to 11.0 years). There were 2 patients with mild to moderate aortic regurgitation. One patient with aortic arch obstruction underwent balloon dilatation 2 years postoperatively. Among those patients who underwent direct anastomoses, 8 (32.0%) patients had pulmonary branch stenosis at 7 months to 1.5 years postoperatively, 12 (48.0%) patients were freedom from surgical reintervention 5.0 to 11.0 years postoperatively. Among those inserting conduits, 7 patients (31.8%) had conduit stenosis at 2.8 to 7.0 years after operation. Reoperations were performed for RVOT in 15 patients and there was no mortality. It is difficult to treat the PTA patients with IAA, intra-mural coronary artery or mechanical ventilation support before operation. The technique of direct anastomosis between pulmonary artery and right ventricle offers the potential growth for RVOT, but bilateral pulmonary branch stenosis may be occurred at earlier period of postoperation in some patients.

Achondroplasia‐hypochondroplasia complex and abnormal pulmonary anatomy

Achondroplasia and hypochondroplasia are two of the most common forms of skeletal dysplasia. They are both caused by activating mutations in FGFR3 and are inherited in an autosomal dominant manner. Our patient was born to parents with presumed achondroplasia, and found on prenatal testing to have p.G380R and p.N540K FGFR3 mutations. In addition to having typical problems associated with both achondroplasia and hypochondroplasia, our patient had several atypical findings including: abnormal lobulation of the lungs with respiratory insufficiency, C1 stenosis, and hypoglycemia following a Nissen fundoplication. After his reflux and aspiration were treated, the persistence of the tachypnea and increased respiratory effort indicated this was not the primary source of the respiratory distress. Our subsequent hypothesis was that primary restrictive lung disease was the cause of his respiratory distress. A closer examination of his chest circumference did not support this conclusion either. Following his death, an autopsy found the right lung had 2 lobes while the left lung had 3 lobes. A literature review demonstrates that other children with achondroplasia-hypochondroplasia complex have been described with abnormal pulmonary function and infants with thanatophoric dysplasia have similar abnormal pulmonary anatomy. We hypothesize that there may be a primary pulmonary phenotype associated with FGFR3-opathies, unrelated to chest size which leads to the consistent finding of increased respiratory signs and symptoms in these children. Further observation of respiratory status, combined with the macroscopic and microscopic analysis of pulmonary branching anatomy and alveolar structure in this patient population will be important to explore this hypothesis.

EBUS-TBNA in the differential diagnosis of pulmonary artery sarcoma and thromboembolism: Figure 1–

To the Editors: We read with interest the correspondence published by Park et al. [1] suggesting a potential role for endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) to differentiate pulmonary artery sarcoma and thromboembolism. Pulmonary artery sarcoma usually has its origin in the pulmonary arterial trunk and extends towards pulmonary branches, and is indeed sometimes difficult to differentiate from chronic thromboembolic disease. However, we believe that the authors’ conclusions suggesting that EBUS-TBNA is safe in this setting are premature. Indeed, such an approach could be associated with significant complications. Even if pulmonary artery sarcoma may mimic acute or chronic pulmonary …

A new technique for the correction of hypoplastic left heart syndrome

Hypoplastic left heart syndrome (HLHS) inevitably results in death within a few weeks of birth, and the surgical treatment for this condition involves three complex surgeries that are associated with a high mortality and cost (1). The mortality rates for the first-stage procedure range from 25-80% at medical centers worldwide. Moreover, many children (possibly as many as 50%, according to hospitals where accurate records are kept) with this disease are not referred for surgery and progress to death within days or weeks (2-4). The two conventional techniques that are used for the Norwood procedure (the first-stage surgical correction) involve the construction of a systemic pulmonary shunt. This procedure performed using the Blalock-Taussig technique leads to a diastolic systemic pulmonary flow that mimics systemic valve insufficiency. When performed using the Sano modification technique, the Norwood procedure involves building a tube between the systemic ventricle and the pulmonary artery; this technique avoids the diastolic systemic pulmonary flow but allows the blood in the lungs to reflux to the single ventricle, which increases the volume overload. This overload associated with ventriculotomy may lead to dysfunction of the ventricle and arrhythmia. Moreover, both techniques necessitate the use of an artificial tube and carry a risk for thrombosis or stenosis (5-9). Additionally, fabrication of the neo-aorta is a laborious technique that requires the extended use of extracorporeal circulation (ECC). Hybrid approaches involving the maintenance of the patent ductus arteriosus with the implantation of a stent (10,11) or the prolonged administration of prostaglandin E1 (12) associated with the banding of the pulmonary branches simplifies the surgical approach but have yielded unsatisfactory results (13,14).

The Use of Reconstructive Surgery to Improve Quality of Life and Survival in Prenatal Hypoplastic Left Heart Syndrome

Outcomes for hypoplastic left heart syndrome have improved substantially in the era of prenatal diagnosis. Current stage 1 survival rates are in excess of 90% in the absence of risk factors. However, fetuses with an intact atrial septum continue to have poor postnatal survival. Accurate diagnosis of these fetuses with an intact atrial septum relies upon careful assessment of the patent foramen ovale, pulmonary venous Doppler flow patterns and branch pulmonary artery Doppler flow patterns. Prenatal and perinatal interventions, such as the placement of an atrial stent in utero or delivery at a center where a stent may be placed immediately after birth to relieve left atrial hypertension, may improve survival in this particularly high-risk group.

Right pulmonary to left pulmonary perfusion ratio after percutaneous pulmonary valve implantation

Background Percutaneous pulmonary valve implantation (PPVI) requires the positioning of a stiff guidewire into one of the pulmonary branch arteries. An infrequent but commonly known complication is the “jailing” of one of the pulmonary branch arteries. However, even without apparent “jailing” of one of the pulmonary branch arteries, we suspect that the technique of stent placements often has an effect on the pulmonary perfusion ratio. The aim of this study was to assess the changes of the pulmonary perfusion ratio and their predictors after PPVI.

McConnell’s sign unveiled

Summary McConnell’s sign is well described in echocardiography as a harbinger of severe RV failure and more extensive arterial thrombus burden but its mechanical basis has never been satifactorily defined despite multiple current theories. CMR RF tissue-tagging now unveils the mechanism. Background Evidence of echocardiographic RV ‘strain’ in the setting of a large, clinically important, often devasting pulmonary embolism (PE) is defined by the presence of paradoxical, often hyperdynamic RV apical contraction in the setting of severely dysfunctional RV function; so denoted ‘McConnell’ ss ign’. Despite its original observation by its namesake in 1996, it has neither been observed via CMR nor more importantly, while many theories exist, mechanistically explained. Hypothesis We hypothesize that McConnell’s sign (MS) is observable utilizing CMR and can be explained via CMR deformational analysis. Methods Modestly stable patients who had CT confirmed large (>one pulmonary branch obstruction and/or saddle PE) were evaluated via echocardiography and CMR. CMR radio-frequency tissue tagging was performed to determine midwall intramyocardial deformation patterns with superimposition of quiver plot technique to define direction and amplitude of myocardial displacements assuming homogenous tissue strain (%S). Results