Disparate activation of the coronary sinus and inferior left atrium during atrial tachycardia after persistent atrial fibrillation ablation: prevalence, pitfalls, and impact on mapping

Persistent atrial fibrillation (AF) ablation may lead to partial disconnection of the coronary sinus (CS). As a result, disparate activation sequences of the local CS versus contiguous left atrium (LA) may be observed during atrial tachycardia (AT). We aimed to evaluate the prevalence of this phenomenon and its impact on activation mapping.

Electroanatomic reconstruction of the left atrium, pulmonary veins, and esophagus compared with the "true anatomy" on multislice computed tomography in patients undergoing catheter ablation of atrial fibrillation

BACKGROUND: Current concepts of catheter ablation for atrial fibrillation (AF) commonly use three-dimensional (3D) reconstructions of the left atrium (LA) for orientation, catheter navigation, and ablation line placement. OBJECTIVES: The purpose of this study was to compare the 3D electroanatomic reconstruction (Carto) of the LA, pulmonary veins (PVs), and esophagus with the true anatomy displayed on multislice computed tomography (CT). METHODS: In this prospective study, 100 patients undergoing AF catheter ablation underwent contrast-enhanced spiral CT scan with barium swallow and subsequent multiplanar and 3D reconstructions. Using Carto, circumferential plus linear LA lesions were placed. The esophagus was tagged and integrated into the Carto map. RESULTS: Compared with the true anatomy on CT, the electroanatomic reconstruction accurately displayed the true distance between the lower PVs; the distances between left upper PV, left lower PV, right lower PV, and center of the esophagus; the longitudinal diameter of the encircling line around the funnel of the left PVs; and the length of the mitral isthmus line. Only the distances between the upper PVs, the distance between the right upper PV and esophagus, and the diameter of the right encircling line were significantly shorter on the electroanatomic reconstructions. Furthermore, electroanatomic tagging of the esophagus reliably visualized the true anatomic relationship to the LA. On multiple tagging and repeated CT scans, the LA and esophagus showed a stable anatomic relationship, without relevant sideward shifting of the esophagus. CONCLUSION: Electroanatomic reconstruction can display with high accuracy the true 3D anatomy of the LA and PVs in most of the regions of interest for AF catheter ablation. In addition, Carto was able to visualize the true anatomic relationship between the esophagus and LA. Both structures showed a stable anatomic relationship on Carto and CT without relevant sideward shifting of the esophagus.

Port-a-Cath perforation of the right atrium closed with an amplatzer ASD occluder

Right atrial perforation can lead to tamponade and death. Closure devices are used for sealing of shunts in the heart. We describe an indwelling catheter that caused perforation of the right atrium and was treated with a percutaneous closure device.

[Wall calcifications of the left heart atrium]

The chest X-ray of a 61-year-old man with severe aortic and mitral stenosis revealed extensive, circularly arranged calcifications in the wall of the left atrial appendage. He died soon after admission to hospital and autopsy confirmed the atrial calcifications in association with severe mitral stenosis. Although such calcification of the left atrial wall is rare, it can be of importance because it may make the usual surgical approach to mitral valve replacement impossible.

Pulmonary veins to left atrium cycle length gradient predicts procedural and clinical outcomes of persistent atrial fibrillation ablation.

BACKGROUND Rapid pulmonary vein (PV) activity has been shown to maintain paroxysmal atrial fibrillation (AF). We evaluated in persistent AF the cycle length (CL) gradient between PVs and the left atrium (LA) in an attempt to identify the subset of patients where PVs play an important role. METHODS AND RESULTS Ninety-seven consecutive patients undergoing first ablation for persistent AF were studied. For each PV, the CL of the fastest activation was assessed over 1 minute (PVfast) using Lasso recordings. The PV to LA CL gradient was quantified by the ratio of PVfast to LA appendage (LAA) AF CL. Stepwise ablation terminated AF in 73 patients (75%). In the AF termination group, the PVfast CL was much shorter than the LAA CL resulting in lower PVfast/LAA ratios compared with the nontermination group (71±10% versus 92±7%; P<0.001). Within the termination group, PVfast/LAA ratios were notably lower if AF terminated after PV isolation or limited adjunctive substrate ablation compared with patients who required moderate or extensive ablation (63±6% versus 75±8%; P<0.001). PVfast/LAA ratio <69% predicted AF termination after PV isolation or limited substrate ablation with 74% positive predictive value and 95% negative predictive value. After a mean follow-up of 29±17 months, freedom from arrhythmia recurrence off-antiarrhythmic drugs was achieved in most patients with PVfast/LAA ratios <69% as opposed to the remaining population (80% versus 43%; P<0.001). CONCLUSIONS The PV to LA CL gradient may identify the subset of patients in whom persistent AF is likely to terminate after PV isolation or limited substrate ablation and better long-term outcomes are achieved.

Stitched to the heart--till intervention do us part

The case report describes the situation where a venous infusion catheter was inadvertently stitched to the lateral wall of the right atrium during valve replacement. A dual percutaneous approach was used to first sever the catheter at the suture and then remove both ends safely. The risk of tearing the suture which would have resulted in tamponade had to be avoided.

Mapping of atrial tachycardias after catheter ablation for atrial fibrillation: use of bi-atrial activation patterns to facilitate recognition of origin

Mapping and ablation of atrial tachycardias (ATs) secondary to catheter ablation of atrial fibrillation (AF) is often challenging due to the complex atrial substrate, different AT mechanisms, and potential origin not only in the left atrium (LA) but also from the right atrium (RA) and the adjacent thoracic veins.

Early repolarization, left ventricular diastolic function, and left atrial size in professional soccer players

Recent data have suggested a relation among long-term endurance sport practice, left atrial remodeling, and atrial fibrillation. We investigated the influence of an increased vagal tone, represented by the early repolarization (ER) pattern, on diastolic function and left atrial size in professional soccer players. Fifty-four consecutive athletes underwent electrocardiography, echocardiography, and exercise testing as part of their preparticipation screening. Athletes were divided into 2 groups according to presence or absence of an ER pattern, defined as a ST-segment elevation at the J-point (STE) > or =0.1 mm in 2 leads. For linear comparisons average STE was calculated. Mean age was 24 +/- 4 years. Twenty-five athletes (46%) showed an ER pattern. Athletes with an ER pattern had a significant lower heart rate (54 +/- 9 vs 62 +/- 11 beats/min, p = 0.024), an increased E/e' ratio (6.1 +/- 1.2 vs 5.1 +/- 1.0, p = 0.002), and larger volumes of the left atrium (25.6 +/- 7.3 vs 21.8 +/- 5.0 ml/m(2), p = 0.031) compared to athletes without an ER pattern. There were no significant differences concerning maximum workload, left ventricular dimensions, and systolic function. Univariate regression analysis revealed significant correlations among age, STE, and left atrial volume. In a stepwise multivariate regression analysis age, STE and e' contributed independently to left atrial size (r = 0.659, p <0.001). In conclusion, athletes with an ER pattern had an increased E/e' ratio, reflecting a higher left atrial filling pressure, contributing to left atrial remodeling over time.

Mitral regurgitation

Mitral regurgitation (MR) involves systolic retrograde flow from the left ventricle into the left atrium. While trivial MR is frequent in healthy subjects, moderate to severe MR constitutes the second most prevalent valve disease after aortic valve stenosis. Major causes of severe MR in Western countries include degenerative valve disease (myxomatous disease, flail leaflet, annular calcification) and ischaemic heart disease, while rheumatic disease remains a major cause of MR in developing countries. Chronic MR typically progresses insidiously over many years. Once established, however, severe MR portends a poor prognosis. The severity of MR can be assessed by various techniques, Doppler echocardiography being the most widely used. Mitral valve surgery is the only treatment of proven efficacy. It alleviates clinical symptoms and prevents ventricular dilatation and heart failure (or, at least, it attenuates further progression of these abnormalities). Valve repair significantly improves clinical outcomes compared with valve replacement, reducing mortality by approximately 70%. Reverse LV remodelling after valve repair occurs in half of patients with functional MR. Percutaneous, catheter-based to mitral valve repair is a novel approach currently under clinical scrutiny, with encouraging preliminary results. This modality may provide a valuable alternative to mitral valve surgery, especially in critically ill patients.

Spatial and functional relationships between air conduits and blood capillaries in the pulmonary gas exchange tissue of adult and developing chickens

The documented data regarding the three-dimensional structure of the air capillaries (ACs), the ultimate sites of gas exchange in the avian lung is contradictory. Further, the mode of gas exchange, described as cross-current has not been clearly elucidated. We studied the temporal and spatial arrangement of the terminal air conduits of the chicken lung and their relationship with the blood capillaries (BCs) in embryos as well as the definitive architecture in adults. Several visualization techniques that included corrosion casting, light microscopy as well as scanning and transmission electron microscopy were used. Two to six infundibulae extend from each atrium and give rise to numerous ACs that spread centrifugally. Majority of the ACs are tubular structures that give off branches, which anastomose with their neighboring cognates. Some ACs have globular shapes and a few are blind-ending tapering tubes. During inauguration, the luminal aspects of the ACs are characterized by numerous microvillus-like microplicae, which are formed during the complex processes of cell attenuation and canalization of the ACs. The parabronchial exchange BCs, initially inaugurated as disorganized meshworks, are reoriented via pillar formation to lie predominantly orthogonal to the long axes of the ACs. The remodeling of the retiform meshworks by intussusceptive angiogenesis essentially accomplishes a cross-current system at the gas exchange interface in the adults, where BCs form ring-like patterns around the ACs, thus establishing a cross-current system. Our findings clarify the mode of gas exchange in the parabronchial mantle and illuminate the basis for the functional efficiency of the avian lung.

[Case report: an exceptional case of a monozygotic thoracopagus parasiticus in a German Holstein calf]

A black and white German Holstein calf displayed a complex double malformation in shape of a thoracopagus parasiticus. By means of a molecular genetic investigation the genesis of the malformation from one zygote could be demonstrated. Both vertebral columns showed a pronounced lordosis, with the vertebral column of one animal ending in a rudimentary head. Close to this rudiment two derivates of branchial arches were found. The two thoracic cavities merged into one "thorax". In the shared thoracic cavity one heart was found. In its right atrium, a cherry-sized structure was found in which heart- and vascular smooth muscles were demonstrated histologically. The aorta split shortly after its origin to provide both animals with one aorta each. The larger pair of lungs was connected with a trachea leading to the head while the smaller pair of lungs originated from a trachea deriving from the rudimentary head. The diaphragm jejunum and split afterwards. The pedigree of the affected animal showed neither inbreeding nor any other affected animal.

Giant coronary artery fistula complicated by cardiac tamponade

A 30 year old female was admitted to the hospital with cardiogenic shock due to cardiac tamponade. A ruptured giant coronary artery fistula (CAF) originating from the left main coronary artery draining into the right atrium was identified as the cause. In this case report we describe the clinical course with emphasis on diagnostic work-up and imaging.

Postmortem radiology of fatal hemorrhage: measurements of cross-sectional areas of major blood vessels and volumes of aorta and spleen on MDCT and volumes of heart chambers on MRI

OBJECTIVE: Autopsy determination of fatal hemorrhage as the cause of death is often a difficult diagnosis in forensic medicine. No quantitative system for accurately measuring the blood volume in a corpse has been developed. MATERIALS AND METHODS: This article describes the measurement and evaluation of the cross-sectional areas of major blood vessels, of the diameter of the right pulmonary artery, of the volumes of thoracic aorta and spleen on MDCT, and of the volumes of heart chambers on MRI in 65 autopsy-verified cases of fatal hemorrhage or no fatal hemorrhage. RESULTS: Most cases with a cause of death of "fatal hemorrhage" had collapsed vessels. The finding of a collapsed superior vena cava, main pulmonary artery, or right pulmonary artery was 100% specific for fatal hemorrhage. The mean volumes of the thoracic aorta and of each of the heart chambers and the mean cross-sectional areas of all vessels except the inferior vena cava and abdominal aorta were significantly smaller in fatal hemorrhage than in no fatal hemorrhage. CONCLUSION: For the quantitative differentiation of fatal hemorrhage from other causes of death, we propose a three-step algorithm with measurements of the diameter of the right pulmonary artery, the cross-sectional area of the main pulmonary artery, and the volume of the right atrium (specificity, 100%; sensitivity, 95%). However, this algorithm must be corroborated in a prospective study, which would eliminate the limitations of this study. Quantitative postmortem cross-sectional imaging might become a reliable objective method to assess the question of fatal hemorrhage in forensic medicine.

Sodium pump reduction correlates with aortic clamp time in pediatric heart surgery

Myocardial depression after cardiac surgery is modulated by cardiopulmonary bypass (CPB) and the underlying heart disease. The sodium pump is a key component for myocardial function. We hypothesized that the change in sodium pump expression during CPB correlates with intraoperative and postoperative laboratory and clinical parameters in neonates and children with various congenital heart defects. Sodium pump isoforms alpha1 (ATP1A1) and alpha3 (ATP1A3) mRNA expression in right atrial myocardium, excised before and after CPB, was quantified. Groups were assigned according to presence (VO group, n = 8) or absence (NO group, n = 8) of right atrial volume overload. CPB and aortic clamp time correlated with postoperative troponin-I values and ICU stay. ATP1A1 (P = 0.008) and ATP1A3 (P = 0.038) mRNA expression were significantly reduced during CPB. Longer aortic clamp times were associated with lower postoperative ATP1A1 (P = 0.045) and ATP1A3 (P = 0.002) mRNA expression. Low postoperative ATP1A1 (P = 0.043) and ATP1A3 (P = 0.002) expressions were associated with high troponin-I values. These results were restricted to the VO group. No correlation of sodium pump mRNA expression was found with the duration of ICU stay or ventilation. The postoperative troponin-I and clinical parameters correlated with the length of CPB, regardless of volume overload. In contrast, only dilated right atrium seemed to be susceptible to CPB in terms of sodium pump expression, showing a reduction during the operation and a correlation of sodium pump with postoperative troponin-I values.

Beneficial cardiovascular effects of endothelin ET(A) receptor blockade in established long-term heart failure after myocardial infarction

Although experimental prevention studies have suggested therapeutic potential of endothelin (ET) antagonists for the treatment of heart failure, the results of clinical trials using ET antagonists on top of standard heart failure medications have been largely disappointing. This experimental study investigated the effects of chronic ET(A) receptor blockade in long-term survivors of myocardial infarction who had developed stable chronic heart failure in the absence of other treatments. Systolic blood pressure, heart rate, organ weights of the right atrium and ventricle, and the lungs were determined, and tissue ET-1 peptide levels were measured in cardiac tissue, lung, and aorta. The results show that chronic blockade of ET(A) receptors stabilizes systolic blood pressure and reverses the heart failure-induced weight increases of right heart chambers and lung. The changes observed occurred independently of tissue ET-1 concentrations and heart rate, suggesting mechanisms independent of local cardiac or pulmonary ET-1 synthesis, which are yet to be identified.