A Rare Report of Hypoplastic Coronary Arteries and Pulmonary Veins: A Case Report and Review of the Literature.

Congenital coronary artery anomalies are estimated to affect about 1% of the general population. Hypoplastic coronary artery disease is an uncommon subset associated with significant mortality regardless whether another major cardiac anomaly is present. In this case report, we present an extremely rare case of an infant with hypoplastic coronary artery disease and hypoplastic pulmonary veins. A literature review pertinent to the clinical findings is also contained herein.

Successful percutaneous cardiac resynchronization despite an occlusive Thebesian valve.

We report the case of a patient with symptomatic heart failure referred after an unsuccessful attempt at cardiac resynchronization therapy. An occlusive Thebesian valve prevented entry into the coronary sinus ostium. Careful analysis of the patient's cardiovascular physiology and anatomy revealed the "fortuitous" presence of a persistent left superior vena cava. Cannulation of this vessel permitted percutaneous retrograde placement of a left ventricular lead into a posterolateral cardiac venous branch resulting in successful cardiac resynchronization. This unique case provides strong evidence that thorough knowledge of cardiac embryology, anatomy, and physiology plays a pivotal role in percutaneous electromechanical intervention for drug-refractory heart failure.

Right coronary artery occlusion during RF ablation of typical atrial flutter.

Right coronary artery (RCA) occlusion and acute myocardial infarction are rare during radiofrequency (RF) ablation of the cavotricuspid isthmus. Ventricular fibrillation (VF) or cardiac arrest in the periprocedural period may be the initial or only clinical manifestation. Septal or lateral RF delivery may increase the risk. We report 2 cases of RCA occlusion during ablation of typical atrial flutter (AFL). Angiographic and anatomical correlations are illustrated. One patient was ablated with a septal approach, the other with a lateral approach, and in each instance the RCA occluded near the ablative lesions. If septal or lateral ablation lines are contemplated during ablation of isthmus-dependent atrial flutter, fluoroscopic or electroanatomic confirmation of catheter position is pivotal. Smaller tipped catheters, energy titration (to minimally effective dose), saline irrigation, or cryoablation should also be considered to help avoid this serious complication.

Prenatal Diagnosis of Uhl Anomaly with Autopsy Correlation.

Uhl anomaly is a rare form of congenital hypoplasia of the right ventricular myocardium. Here, we report, a rare finding in fetal cardiac ultrasound in a 33-year-old woman who presented at 20 weeks' of gestation. A diagnosis of Uhl anomaly was made. An autopsy was performed at 23weeks gestation after obtaining permission for medicolegal termination of pregnancy. Histopathological examination confirmed the diagnosis. Diagnosing Uhl anomaly in fetal life is essential since mortality and survival mainly depend on the severity of right ventricle dysfunction related to, the either partial or complete absence of the myocardium. Hence, surviving cases need to be followed up carefully and counselled accordingly.

Relationship of Normal Aortic Valve Cusp Dimensions: A Tool to Optimize Cusp Reconstruction Valvuloplasty.

Outcomes of surgical aortic valvuloplasty hinge primarily on optimal leaflet design. Imprecise valve reconstruction can result in insufficiency or stenosis. Predicting postrepair leaflet parameters from pre- or intraoperative readily measurable valve dimensions could result in improved reconstruction. This study analyzes the relationships between different parameters of the normal aortic valve to establish a method of deriving the optimal dimensions of the reconstructed leaflet following valvuloplasty. Morphologic analysis of the normal aortic valve was performed on 50 autopsy specimens. The following parameters were measured: circumference at ventriculoaortic junction, intercommissural circumferential distance (IC), commissural height, leaflet free-margin length (L1-length of the free margin of each leaflet), cusp attachment length (L2-cusp attachment length at the ventriculoaortic junction), and leaflet height (A-ie, the vertical or cephalocaudal distance along the convex surface of the leaflet from the midpoint of the leaflet free margin to the midpoint of the cusp attachment). Univariate linear regression analysis was used to test the interdependence of leaflet dimensions. The leaflet free-margin length L1 correlated strongly with the corresponding IC: r = 0.74, 0.81, and 0.79 for noncoronary, right coronary, and left coronary leaflets, respectively; P = 0.000. Leaflet height A and cusp attachment length L2 also correlated well with the corresponding IC: A-IC, r = 0.56, 0.74, and 0.66; and L2-IC, r = 0.78, 0.85, and 0.80 for noncoronary, right coronary, and left coronary cusps respectively; P = 0.000. Parameters required to construct an aortic valve leaflet can be reliably derived from the IC, which can be easily measured perioperatively. Using this as a basis for leaflet reconstruction might optimize the leaflet graft design process, compensate for pathologic variations in aortic annulus size and commissural height, and could result in better coaptation of the valve leaflets.

His electrogram alternans reveal dual atrioventricular nodal pathway conduction during atrial fibrillation: the role of slow-pathway modification.

BACKGROUND: Traditional tools to study dual-pathway atrioventricular nodal (AVN) electrophysiology are not applicable in subjects with permanent atrial fibrillation (AF). The presence of fast-pathway (FP) and slow-pathway (SP) wavefronts and their possible modification remain uncertain in this condition. We demonstrated previously that His electrogram (HE) alternans can determine whether the FP or the SP reaches the His bundle on a beat-by-beat basis. We have now applied this novel index to monitor dual-pathway conduction and the effects of SP modification during AF. METHODS AND RESULTS: In 12 rabbit AVN preparations, HE alternans were confirmed during a standard A(1)A(2) pacing protocol. During AF, in 9 of the 12 hearts, HE alternans indicated the presence of dual pathways. Successful SP modification guided by the HE alternans eliminated the SP, resulting in a predominantly FP conduction during AF in all hearts. This increased the average His-His interval (204+/-14 versus 276+/-51 ms, P<0.001). Morphological studies revealed that SP modification damaged only the posterior extension of the AVN. CONCLUSIONS: We have demonstrated for the first time in rabbits that HE alternans permit "visualization" of dual-pathway electrophysiology and confirmed the presence of both FP and SP wavefronts during AF. This novel index has been used in a selective SP ablation that resulted in a significant slowing of the ventricular rate. HE alternans provide a new insight into the mechanisms of AVN conduction and could guide AVN modification for ventricular rate control in AF clinically.

Atrioventricular nodal fast pathway modification: mechanism for lack of ventricular rate slowing in atrial fibrillation.

OBJECTIVES: Atrioventricular node (AVN) modification is one of the alternatives for ventricular rate control in patients with drug refractory atrial fibrillation (AF). However, the underlying mechanisms, and in particular the role of the dual pathway electrophysiology is not clear. By using a novel index, His electrogram (HE) alternans, we have previously demonstrated in rabbits that both the slow (SP) and the fast pathways (FP) are involved in AVN conduction during AF. This electrophysiological-morphological study was designed to address the role of selective FP ablation on AVN conduction during AF. METHODS AND RESULTS: In 12 rabbit AVN preparations dual pathway conduction was confirmed by HE alternans during A1A2 pacing protocol, as well as during AF. On average 48% of the conducted beats during AF utilized the FP. Selective FP ablation (n=12) guided by HE alternans resulted in only-SP conduction, with longer AVN conduction time at basic beats, but without change of AVN effective refractory period (ERP). Interestingly, despite elimination of all FP-conducted beats during AF, the selective FP ablation allowed previously concealed SP beats to be conducted, resulting in little net effect on the ventricular rate (average His-His interval 199+/-10 ms before versus 201+/-13 ms after FP ablation, p>0.05). Morphological evidence indicated that FP ablation created lesions within the transitional cells of the superior approaches at the junction between the central fibrous body and the AVN. However, extension of FP ablation lesion into the compact AVN domain resulted in non-selective AVN modification and slowing of ventricular rate during AF. CONCLUSIONS: Despite its longer ERP, FP is responsible for a substantial number of ventricular beats during AF. However, selective FP ablation has a minor effect on ventricular rate. The most likely mechanism for this phenomenon is that FP ablation allows previously concealed SP beats to be conducted. On the other hand, ventricular rate slowdown could be achieved if FP ablations caused collateral damage in the compact node. This study highlights the usefulness of HE alternans as a novel tool to monitor dual pathway conduction during AF and to guide AVN modification.

Echocardiographic diagnosis and prognosis of fetal left ventricular noncompaction.

BACKGROUND: Left ventricular noncompaction (LVNC) has rarely been described in the fetus. METHODS: The presence of associated congenital heart disease and rhythm disturbance was identified and the presence of heart failure was assessed using the cardiovascular profile score in all fetuses with LVNC presenting from January 1999 to July 2010. The left ventricle was divided into 12 segments-four segments each at the base, midpapillary, and apical regions-in the short-axis view to calculate the noncompaction/compaction ratio for each segment. RESULTS: Of 24 fetuses with LVNC included in the study, 22 had significant congenital heart disease, and 15 had complete heart block. Of the 16 patients with adequate follow-up and not electively terminated, 12 (81%) died or progressed to heart transplantation. The average noncompaction/compaction ratios were 2.02 in patients who died or underwent heart transplantation and 1.67 in survivors (P = .2034). Fifty-seven of 93 measured segments (61%) of the left ventricle in the patients who died or underwent heart transplantation had noncompaction/compaction ratios ≥ 2 compared with five of 17 measured segments (29%) in survivors (P = .0837). The average cardiovascular profile score was 6. The apical region had greater involvement of noncompaction than the midpapillary and basal regions, with ratios of 2.27, 2.14, and 1.10, respectively (P = .00035). CONCLUSIONS: Fetuses with LVNC have a poor prognosis that may be related to associated congenital heart disease, increased segmental involvement of noncompaction, and complete heart block and can be predicted by the cardiovascular profile score.

Three-dimensional transesophageal echocardiography of atrial septal defect: a qualitative and quantitative anatomic study.

BACKGROUND: Real-time three-dimensional (3D) transesophageal echocardiography (TEE) was used to analyze atrial septal defect (ASD) with 4 goals: (1) to determine feasibility, (2) to analyze the accuracy of qualitative and quantitative data, (3) to assess strengths and weaknesses of the available modes of 3D TEE, and (4) to provide 3D transesophageal echocardiographic reference images. METHODS: Sixty-five patients with ASDs (age, 5-64 years; weight, 20-114 kg; body surface area, 0.8-2.4 m(2)) underwent 3D TEE during catheter intervention or surgery. Three-dimensional transesophageal echocardiographic formats included live 3D, 3D zoom, and full-volume 3D modes. Qualitative and quantitative analysis of the 3D data was compared with two-dimensional echocardiographic data and intraoperative inspection. RESULTS: Diagnostic-quality 3D TEE was successfully performed in all 65 patients. Fifty had secundum ASDs and 15 had other ASD types (seven sinus venosus, six primum, one common atrium, and one coronary sinus ASD). ASD type and location were correctly diagnosed in all patients. ASD shape and orientation were confirmed in 21 patients at surgery. Quantitative analysis of ASDs successfully demonstrated rims and changes in dimensions from systole to diastole. Live 3D mode had the highest volume rate, the best transgastric views, and the best views during device deployment but was limited by small sector size. Three-dimensional zoom mode allowed precropped live 3D images but was limited by slow volume rate. Full-volume mode had the best views of large defects and surrounding anatomy. However, it was limited by stitch artifact and required postacquisition cropping. CONCLUSIONS: Three-dimensional TEE is feasible and accurate. Each of the 3D transesophageal echocardiographic modalities has strengths and limitations.

Cardiomyopathy in multiple Acyl-CoA dehydrogenase deficiency: a clinico-pathological correlation and review of literature.

Multiple acyl-CoA dehydrogenase deficiency (MADD) is a rare autosomal recessive defect of the electron transfer flavoprotein or ubiquinone oxidoreductase, resulting in abnormal fatty acid, amino acid, and choline metabolism, leading to metabolic acidosis, hypoglycemia, "sweaty-feet" odor, and early neonatal deaths. This report presents a child diagnosed with this disease at birth by newborn screening using the mass spectrometer, who died suddenly at the age of 6 months. The echocardiogram revealed pericardial effusion, thickened ventricular musculature, and insufficiency of both the atrio-ventricular valves. The autopsy showed immense cardiomegaly, fatty infiltration, and hypertrophy of the ventricles. This is the first detailed case report of clinico-pathological correlation of MADD in an infant and brings into light a rare form of cardiomyopathy as a differential diagnosis in critically ill patients.

Extensive left ventricular to coronary artery connections in hypoplastic left heart syndrome.

We demonstrate the echocardiographic features of a rare case of very extensive left ventricular to coronary arterial connections (VCC) to both the right and left coronary arteries in a fetus and subsequent neonate with hypoplastic left heart syndrome (HLH). The right coronary artery, after receiving multiple VCC supplied the only antegrade ascending aortic flow. The left main coronary artery was very hypoplastic and the left anterior descending coronary artery was dilated and tortuous with multiple large VCC. The left circumflex coronary artery arose exclusively from its own VCC. To our knowledge this is the first such echocardiographic demonstration of HLH with extensive bilateral VCC and coronary artery stenosis and interruption.

Morphologic study of the ascending aorta and aortic arch in hypoplastic left hearts: surgical implications.

OBJECTIVES: The ascending aorta and aortic arch in patients with hypoplasia of the left heart are hypoplastic as a result of diminished blood flow. In this study, the presence and degree of obstruction owing to areas of narrowing or infolding within the diminutive aorta are quantified, and their surgical significance is discussed. METHODS: Ninety-six specimens with hypoplasia of the left heart were studied and measurements were taken at specified sites to evaluate areas of narrowing. Quantitative assessments of infoldings and their contribution to obstruction of flow are made. RESULTS: Narrowing of the distal ascending aorta was found in 60 (62.5%) specimens, with a decrease in circumference of the distal ascending aorta (0.72 +/- 1.06 mm) present when compared with its midpoint (P < .05). Tissue infolding at the orifice of the brachiocephalic artery and its junction with the distal ascending aorta was observed in 56 (58.3%) hearts, with major infolding in 29 (30.2%) and minor infolding in 27 (28.5%). Tissue infolding at this site correlated with a smaller ascending aorta (P < .001) but not with narrowing in the distal ascending aorta (P = .53). Ductal coarctations were detected in 77 (81.1%) specimens. Their presence correlated with a smaller diameter of the ascending aorta (P < .05), and their severity correlated with the presence of aortic and mitral valvular atresia (P < .05). CONCLUSIONS: Important areas of obstruction in the ascending aorta in patients with hypoplasia of the left heart were found, and their pathogenesis is discussed. The findings highlight the importance of incorporating the ascending aorta into the aortic reconstruction at the time of initial palliation for patients with hypoplasia of the left heart.

Computer three-dimensional reconstruction of the atrioventricular conduction system.

The human atrioventricular conduction system (AVCS), which includes the AV node and its approaches, AV bundle (penetrating, branching, and bifurcating parts), and the bundle branches, is a curved complex structure that has not been reconstructed in three dimensions using computer technology. Microscopic slides of every 40(th) serial section (cut at 7 micron level) of the AVCS were digitized into 600 dots/inch color images. External outlines of each section were manually segmented using commercially available three-dimensional rendering software (Rhinoceros). The AVCS was traced from light microscopy and superimposed onto the external outlines. To account for inherent errors in histological slide preparation, an optimization procedure was used to align external outlines of all sections. The optimal rotation and translation of each section was established by maximizing area of overlap between adjacent sections. A sequential one-dimensional minimization algorithm was used for optimization. Rotation and translation values were then used to align external outlines and the superimposed conduction system, reconstructing the AVCS in three-dimensions. To validate the method, the algorithm was applied to a digitized image transformed with known translations and rotations. The validation procedure demonstrated that each test image aligned in translations and to within 0.01 degree in rotations. Spatial error determined by resolution of the digitized images was +/-0.5/600 inch (+/-21 microns). Three-dimensional reconstruction of every 40th serial section clearly demonstrated the complex curved shape of the AVCS. Three-dimensional reconstruction of the human and canine AVCS permits accurate pathological and electrophysiological correlation of the conduction system.