Usefulness of a Pulse Oximeter and Multimodality Imaging for Diagnosing Platypnea-orthodeoxia Syndrome.

Platypnea-orthodeoxia syndrome (POS) is a rare disease characterized by dyspnea and hypoxemia in orthostatism that improves in the recumbent position. We herein report an 81-year-old woman with dyspnea in the upright position following thoracic vertebral compression fractures. After the patient's daughter brought a recording showing decreasing SpO2 (peripheral capillary oxygen saturation) in the upright position as measured by a portable pulse oximeter outside the hospital, a small atrial septal defect (ASD) was detected. A contrast echocardiogram and four-dimensional flow magnetic resonance imaging demonstrated a right-to-left shunt. The patient's symptoms dramatically improved after percutaneous ASD closure. In conclusion, such new technologies are useful for diagnosing POS.

Value of 3D echocardiography in the diagnosis of arrhythmogenic right ventricular cardiomyopathy.

AIMS: The 2010 Task Force Criteria (TFC) require that both right ventricular (RV) regional wall-motion abnormalities (WMA) and specific RV size cut-offs be met in order to fulfil one of the major criterion for arrhythmogenic right ventricular cardiomyopathy (ARVC) diagnosis. Currently, 2D echocardiography (2DE) and cardiovascular magnetic resonance imaging (cMRI) are used to determine if these criteria are met. Little is known about the diagnostic value of 3D echocardiography (3DE) in ARVC. The aim of this study was to determine whether a combination of 2DE-3DE is non-inferior to the currently used 2DE-cMRI combination in the diagnosis of patients with ARVC. METHODS AND RESULTS: Thirty-nine individuals (47±15 years) with suspected ARVC underwent evaluation of the RV with cMRI, 2DE, and 3DE. 3DE and cMRI were independently used to obtain RV volumes, ejection fraction (EF) and determine the presence of segmental RV WMA. Studies were blindly classified as meeting criteria for ARVC in accordance with the 2010 TFC. Kappa statistics were used to test the concordance between 2DE-cMRI and 2DE-3DE approaches. Using the 2DE-cMRI approach, 3/39 were not affected, 5/39 possible, 8/39 borderline, and 23/39 definite ARVC. The proposed 2DE-3DE approach yielded 5/39 not affected, 7/39 possible, 8/39 borderline, and 19/39 definite diagnoses. The two approaches were highly concordant (k = 0.71; 95% confidence interval: 0.44-0.84). Although 3DE underestimated RV volumes in comparison with cMRI, interfering, in some instances with the fulfilment of a major criterion, it was able to identify more RV WMA (28/39) than 2DE (11/39), with a detection-rate comparable to cMRI (33/39) highlighting a unique advantage. CONCLUSION: The combination of 2DE-3DE for ARVC diagnosis is comparable to the conventional 2DE-cMRI approach. 3DE should be performed in all suspected ARVC patients to aide in the detection of WMA.

Single-stage arterial switch operation conversion with dextro-transposition of the great arteries and pulmonary arterial hypertension due to baffle leak after a Senning procedure.

Patients who have undergone an atrial switch operation for dextro-transposition of the great arteries (dTGA) sometimes suffer from right ventricular dysfunction, tricuspid regurgitation, arrhythmias, or baffle leaks. We report the first case of single-stage arterial switch operation conversion in an adult patient with dTGA and pulmonary arterial hypertension (PAH) due to a baffle leak after a Senning procedure. Perioperative mechanical circulatory support was required for 3 weeks. Although chronic kidney disease persisted, her left ventricular function and pulmonary hypertension improved over the first postoperative year. This is a rare case, and we believe that the patient's PAH might have helped the left ventricle withstand systemic pumping for over two decades. Learning objective: Patients with dextro-transposition of the great arteries may face problems after an atrial switch operation because their right ventricle is responsible for systemic pumping. Staged arterial switch operation conversion is a strategy that can combat these problems but increases the risk of perioperative mortality. Pulmonary arterial hypertension allows for single-stage arterial switch operation, but the operative risk may be higher.

Short Coaptation Length is a Predictor of Recurrent Mitral Regurgitation After Mitral Valve Plasty.

BACKGROUND: Long-term predictors of recurrent mitral regurgitation (MR) after mitral valve plasty (MVP) remain to be elucidated. This study sought to determine the prognostic factors of recurrent MR during long-term follow-up after MVP, by analysing findings of three-dimensional transoesophageal echocardiography (TEE) conducted after MVP. METHODS: This study analysed 207 patients who underwent MVP for A2 and/or P2 prolapse and received TEE before discharge. Recurrent MR was defined as moderate or worse regurgitation detected by annual transthoracic echocardiography. RESULTS: During a median follow-up period of 49 months after MVP, 18 patients experienced recurrent MR and six patients needed reoperation. In the recurrent group, 16 of 18 patients showed less than moderate MR before discharge. Patients in the recurrent group underwent repair for worse MR (effective orifice area, 54±19 vs 44±16 mm2; p=0.01) and had shorter A2-P2 coaptation length (5.3±1.4 vs 7.3±1.5 mm; p<0.001) after MVP compared with the non-recurrent group. Cox proportional hazards regression analysis identified the A2-P2 coaptation length as significant risk of recurrent MR (coaptation length increase: HR, 0.44; 95% CI, 0.32-0.59; p<0.0001). The receiver operator characteristics curve demonstrated that a coaptation length of <5.6 mm had 78% sensitivity and 89% specificity for predicting recurrent MR. CONCLUSION: Coaptation length measured by post-MVP TEE predicted the tendency of recurrent MR. Patients with short coaptation length should be carefully monitored, even when residual MR is less than moderate after MVP.

Impact of Severe Pulmonary Arterial Hypertension on the Left Heart and Prognostic Implications.

BACKGROUND: Severe pulmonary arterial hypertension (sPAH) results in a dilated and dysfunctional right ventricle (RV) together with a small left ventricle (LV) with preserved systolic function. RV size and function parameters have an established association with poor prognosis in sPAH. We sought to determine the impact of RV geometry and function on LV mechanics and its relationship with mortality. METHODS: We studied 114 patients (54 ± 13 years) with sPAH, normal LV ejection fraction (LVEF), and complete two-dimensional transthoracic echocardiograms (TTE) and compared them with 70 normal controls of similar age and gender distribution. TTE measurements of atrial sizes, ventricular volumes and function, tricuspid and mitral regurgitation (TR, MR), and LV diastolic function were performed. Speckle-tracking strain was measured in all four chambers, including LV global longitudinal strain (GLS). Cox proportional hazards regression with forward selection was performed to determine the associations between measured indices and mortality over a 20-month follow-up period. Kaplan-Meier curves were generated for variables most associated with death. RESULTS: Compared with controls, sPAH patients had greater TR severity and right-chamber size with worse function. Of note, LVEF was normal in both groups. Left atrial peak strain and LV GLS were reduced in sPAH, with greater reductions in nonsurvivors. In multivariate analysis, right atrial volume index (hazard ratio [HR] = 1.02 [CI, 1.01-1.04], P < .01), RV free-wall strain (HR = 1.08; CI [1.01-1.15]; P = .03), and LV GLS (HR = 1.11 [CI, 1.01-1.22]; P = .04) were independently associated with mortality. CONCLUSIONS: Although PAH is predominantly a right heart disease, in our cohort of sPAH with normal LVEF, LV GLS was independently associated with death in addition to RV and right atrial abnormalities. These findings indicate that the role of left heart dysfunction in sPAH may be underappreciated in clinical practice.

Liver disease secondary to congenital heart disease in children.

Introduction: Hepatic fibrosis and hepatocellular carcinoma (HCC) can develop in children with congenital heart disease. Although hepatic fibrosis and HCC are prone to develop after the Fontan operation, they can also develop in patients suffering from congenital heart disease who have not undergone Fontan operation. Area covered: The history of cardiac hepatopathy including Fontan-associated liver disease is described. Patient characteristics, liver histology, imaging examinations and blood tests are reviewed to elucidate the mechanism of cardiac hepatopathy. In addition, a flowchart for the follow-up management of cardiac hepatopathy in children with congenital heart disease is proposed. Expert opinion: Congestion and low cardiac output are the main causes of cardiac hepatopathy. Advanced hepatic fibrosis is presumed to be associated with HCC. HCC can develop in both adolescents and young adults. Regardless of whether the Fontan operation is performed, children with a functional single ventricle and chronic heart failure should be regularly examined for cardiac hepatopathy. There is no single reliable laboratory parameter to accurately detect cardiac hepatopathy; hepatic fibrosis indices and elastography have shown inconsistent results for detection of this disease. Further studies using liver specimen-confirmed patients and standardization of evaluation protocols are required to clarify the pathogenesis of cardiac hepatopathy.

[Medium-remote Term Results of the Atrioventricular Valve Replacement with Mechanical Valve for Functional Single Ventricles].

We prospectively investigated the relation of adaptation, timing of atrioventricular valve replacement (AVVR), valve type, size, durability of replacement valve, and preoperative cardiac function with prognosis of AVVR. The subjects included 26 patients[ 15.5 years old( day 2-43 years)] with functional single ventricle who underwent AVVR at our institution between August 1996 and January 2014. Of these patients, 24 had regurgitation, whereas 2 had stenosis. Of 7 patients who died, 3 were infants who died in the postoperative acute phase, and all of them had severe heart failure at the preoperative stage. The 5-year survival rate was 67% as assessed by Kaplan-Meier curve. On univariate analysis of the preoperative data, pulmonary artery pressure (PAP), pulmonary capillary wedge pressure, age at operation, body height, and body weight were significant risk factors for death;of these, only PAP remained in the last model for multiple regression analysis. AVVR for regurgitation is supposed to reduce cardiac volume load and help improve prognosis. Atrioventricular valve plasty or replacement should be performed prior to the development of severe heart failure.

Systemic ventricular morphology-associated increased QRS duration compromises the ventricular mechano-electrical and energetic properties long-term after the Fontan operation.

OBJECTIVES: To evaluate the impact of systemic ventricular (SV) morphology on mechano-electrical interaction (MEI) and compare the results with clinical profiles in Fontan patients. BACKGROUND: Abnormal ventricular MEI causes systolic dysfunction of the right and left ventricles (RV, LV). METHODS: We evaluated serial changes (up to 15 years post-Fontan operation) in QRS duration (QRS-d, ms), catheterization-based hemodynamics and SV performance in 77 patients and compared them with 36 referents. RESULTS: Preoperative QRS-d was wider in the Fontan patients (86+/-14 vs. 64+/-9, p<0.001) and steadily increased for the next 15 years (107+/-25 vs. 85+/-9, p<0.001). QRS-d was wider in non-LV type SV patients than those with LV morphology (p<0.05) with a positive association with age at repair (p<0.001). SV contractility (Ees) improved in the RV and LV groups (p<0.05), during the next 10-year Ees, ventriculoarterial coupling (Ea/Ees) and ventricular efficiency (SW/PVA) were superior in the LV group. QRS-d and its long-term change correlated with the corresponding SV volume and change (p<0.01), respectively, while the immediate postoperative volume reduction did not result in the QRS-d shortening. QRS-d correlated with Ees, Ea/Ees, SW/PVA, and peak oxygen uptake (VO(2)) (p<0.001) and QRS-d was one of the main determinants of peak VO(2) (r=-0.48, p<0.001). CONCLUSIONS: SV morphology-associated wide QRS-d compromises the MEI as well as energetic properties long-term after the Fontan operation, especially in non-LV type patients.

Malignant perinatal variant of long-QT syndrome caused by a profoundly dysfunctional cardiac sodium channel.

BACKGROUND: Inherited cardiac arrhythmia susceptibility contributes to sudden death during infancy and may contribute to perinatal and neonatal mortality, but the molecular basis of this risk and the relationship to genetic disorders presenting later in life is unclear. We studied the functional and pharmacological properties of a novel de novo cardiac sodium channel gene (SCN5A) mutation associated with an extremely severe perinatal presentation of long-QT syndrome in unrelated probands of different ethnicity. METHODS AND RESULTS: Two subjects exhibiting severe fetal and perinatal ventricular arrhythmias were screened for SCN5A mutations, and the functional properties of a novel missense mutation (G1631D) were determined by whole-cell patch clamp recording. In vitro electrophysiological studies revealed a profound defect in sodium channel function characterized by approximately 10-fold slowing of inactivation, increased persistent current, slowing of recovery from inactivation, and depolarized voltage dependence of activation and inactivation. Single-channel recordings demonstrated increased frequency of late openings, prolonged mean open time, and increased latency to first opening for the mutant. Subjects carrying this mutation responded clinically to the combination of mexiletine with propranolol and survived. Pharmacologically, the mutant exhibited 2-fold greater tonic and use-dependent mexiletine block than wild-type channels. The mutant also exhibited enhanced tonic (2.4-fold) and use-dependent block ( approximately 5-fold) by propranolol, and we observed additive effects of the 2 drugs on the mutant. CONCLUSIONS: Our study demonstrates the molecular basis for a malignant perinatal presentation of long-QT syndrome, illustrates novel functional and pharmacological properties of SCN5A-G1631D, which caused the disorder, and reveals therapeutic benefits of propranolol block of mutant sodium channels in this setting.

Comparison of late post-operative cardiopulmonary responses in the Fontan versus ventricular septation for double-inlet left ventricular repair.

Ventricular septation (VS) and the Fontan procedure are alternatives for definitive repair in patients with double-inlet left ventricle; although VS is theoretically preferable, the current preference in practice is the Fontan procedure. However, the long-term outcomes of both procedures remain unclear. To address this issue, cardiopulmonary responses during exercise were measured in patients with double-inlet left ventricle, and the impact of the type of procedure performed, Fontan or VS, on long-term exercise capacity and late postoperative clinical profiles was assessed. Fourteen post-Fontan patients (mean age 17+/-6 years) and 13 VS patients (mean age 19+/-4 years) underwent exercise testing. Of the 13 VS patients, 5 required atrioventricular valve replacement (AVVR), and 7 required pacemaker implantation. Although no difference in peak oxygen uptake was found between the VS and Fontan patients, peak oxygen uptake was higher in VS patients without AVVR (30+/-8 ml/kg/min) than in VS patients with AVVR (19+/-1 ml/kg/min) and Fontan patients (22+/-6 ml/kg/min) (p<0.01). There was no significant difference in peak oxygen uptake between the VS patients with and without pacemaker implantation (p=0.09). The clinical profiles of the VS and Fontan patients were similar in terms of medication and freedom from tachyarrhythmias or reoperations during the follow-up period. In conclusion, the data suggest that VS without AVVR provides excellent future exercise capacity in selected patients with double-inlet left ventricle.

Heart rate dynamics during and after exercise in postoperative congenital heart disease patients. Their relation to cardiac autonomic nervous activity and intrinsic sinus node dysfunction.

BACKGROUND: Abnormal exercise-related heart rate (HR) dynamics, that is, blunted exercise HR response, lower peak HR, and delayed HR recovery after exercise, are associated with high morbidity and mortality in adults with acquired and congenital heart disease (CHD). However, the precise mechanisms underlying the abnormal HR dynamics remain unclear. OBJECTIVES: The purpose of this study is to evaluate the precise contribution of cardiac autonomic nervous activity (CANA) and sinus node function on exercise-related HR dynamics in postoperative patients with CHD. METHODS: We analyzed our previous data in 53 postoperative patients with CHD who had undergone pharmacologic evaluation, including intrinsic HR, and compared the results with HR dynamics. RESULTS: Intrinsic HR (84% +/- 11%) was lower than the expected value and independently correlated with resting HR (P < .05). Univariate analysis demonstrated that all CANA indices significantly correlated with most HR dynamic parameters. On multivariate analysis, basal parasympathetic nervous activity significantly influenced all HR dynamics (P < .05-.0001), except for peak HR, whereas postsynaptic beta sensitivity of the sinus node significantly influenced all HR dynamics (P < .05-.001), except for early HR recovery. Resting plasma norepinephrine significantly correlated with all HR dynamics (P < .05-.001), except for resting HR. CONCLUSIONS: Lower resting and peak HRs are independently associated with intrinsic sinus node dysfunction and abnormal sympathetic CANA, respectively. A blunted HR increase and delayed early HR recovery are independently associated with impaired sympathetic and parasympathetic CANAs with the greater influence on a blunted exercise HR increase.

Impact of central hypercapnic chemosensitivity on enhanced ventilation in patients after the Fontan operation.

BACKGROUND: Central hypercapnic chemosensitivity (Chemo) influences the enhanced ventilatory and sympathetic responses in heart failure patients; however, its influence on these responses in Fontan patients is unknown. OBJECTIVES: To measure Chemo and compare the results with rest and exercise ventilatory characteristics in Fontan patients. METHODS AND RESULTS: We measured Chemo (l/min/mmHg), hemodynamics, pulmonary function, cardiac autonomic nervous and neurohumoral activities and compared the results with the ventilatory response during exercise in 42 Fontan patients and 12 referents. Chemo did not differ significantly between the Fontan patients (1.5 +/- 0.9) and referents (1.3 +/- 0.4). However, a higher Chemo in addition to lower resting arterial oxygen saturation (SaO(2)) and higher dead space ventilation (Vd/Vt) independently determined a higher resting minute ventilation (VE) and, except for the Chemo, these factors also independently determined the higher resting ventilatory equivalent for carbon dioxide output (VE/VCO(2)) (p<0.05-0.001). At peak exercise, the higher Chemo as well as the higher peak Vd/Vt and aerobic exercise capacity independently determined the higher peak VE and VE/VCO(2) (p<0.01-0.001). Among cardiac autonomic and neurohumoral activities, only the higher plasma norepinephrine concentration was associated with higher Chemo in Fontan patients (r=0.40, p<0.01) and age was correlated positively with Chemo in the high Chemo (> or =2.1) Fontan patients (n=10). CONCLUSIONS: In addition to lower SaO(2) and higher Vd/Vt, an increased Chemo associated with sympathetic activation has a significant impact on accelerated rest and exercise ventilation in some Fontan patients, especially in adult patients.