A case of surgically resected cardiac rhabdomyoma with progressive left ventricular outflow tract obstruction.

Cardiac rhabdomyoma is the most prevalent cardiac tumors in the pediatric population, in close association with tuberous sclerosis complex. It is usually detected antenatally or postnatally by echocardiography. Clinical presentations depend greatly on the size and position of the tumor mass. Interestingly, rhabdomyoma has a propensity to regress spontaneously and is not usually operated upon, unless the patient becomes hemodynamically compromised. Herein, we report an unusual case of surgically treated cardiac rhabdomyoma in a baby boy presented at birth with a progressive enlarging intraventricular mass, complicated with left ventricular outflow tract obstruction 7 weeks later. Histopathological examination of the intracardiac mass revealed sheets of tumor cells with spider-like morphology (known as "spider cells"), confirmed the diagnosis of rhabdomyoma. Close disease monitoring of patient's hemodynamic status in a newly diagnosed cardiac rhabdomyoma is inevitable as the tumor, although rare, may progress.

Primary undifferentiated spindle cell sarcoma obstructing the right ventricular outflow tract.

BACKGROUND: Primary undifferentiated spindle cell sarcoma in the right ventricle is an extremely rare tumor. Radical surgical excision is the optimal treatment for long-term survival due to poor response to chemotherapy or radiotherapy at an advanced stage. CASE PRESENTATION: A 42-year-old man with no previous medical history presented with mild dyspnea on exertion and abdominal distension that lasted a week. Computed tomography (CT) revealed a huge homogeneous mass completely obstructing the right ventricle and extending into the pulmonary trunk. However, he suddenly collapsed the next day while on his way to an echocardiography. An extracorporeal membrane oxygenation (ECMO) device was inserted percutaneously and ECMO support was urgently initiated. Based on consideration of right ventricular outflow tract (RVOT) obstruction in the initial CT scan, we decided to remove the mass from the right ventricle immediately. The main mass was resected to relieve the RVOT obstruction, and after the operation, the ECMO was removed from the operation room. However, the patient failed to regain consciousness and electroencephalography (EEG) and subsequent magnetic resonance imaging (MRI) indicated severe hypoxic brain damage. We assume CPR was unsuccessful because the mass completely blocked the RVOT. Pathology revealed the mass was an undifferentiated spindle cell sarcoma. CONCLUSIONS: We present the case of a 42-year-old male with cardiac arrest due to right ventricular outflow tract obstruction by a tumor of the right ventricle. Surgical resection was performed and in histopathology it was proved to be an undifferentiated spindle cell sarcoma.

Cardiac AA amyloidosis in a patient with obstructive hypertrophic cardiomyopathy.

Cardiac amyloid A (AA) amyloidosis is rare. We present the case of a 72-year-old woman with obstructive hypertrophic cardiomyopathy (HCM) and biopsy-proven renal AA amyloidosis whose dyspnea and exercise intolerance had worsened over the previous year. Her AA amyloidosis was suspected to be secondary to chronic diverticulitis for which she had undergone hemicolectomy and sigmoidectomy 3 years prior. Echocardiographic findings were consistent with worsening left ventricular outflow tract obstruction at rest. Cardiac magnetic resonance imaging revealed patchy areas of midwall late gadolinium enhancement. Right ventricular endomyocardial biopsy did not reveal amyloid deposition, and cardiac technetium-99m pyrophosphate scintigraphy did not suggest transthyretin amyloidosis. The patient underwent septal myectomy with resection of an accessory papillary muscle. Pathological examination of the myectomy specimen was consistent with HCM. In addition, there was a thick layer of diffuse endocardial and vascular amyloid deposition that was identified as AA type by laser-microdissection with liquid chromatography-coupled tandem-mass spectrometry. This case report highlights the presence of 2 distinct disease processes occurring simultaneously and the importance of tissue diagnosis of AA amyloidosis, a condition that is not commonly associated with HCM.

Gata4 regulates hedgehog signaling and Gata6 expression for outflow tract development.

Dominant mutations of Gata4, an essential cardiogenic transcription factor (TF), were known to cause outflow tract (OFT) defects in both human and mouse, but the underlying molecular mechanism was not clear. In this study, Gata4 haploinsufficiency in mice was found to result in OFT defects including double outlet right ventricle (DORV) and ventricular septum defects (VSDs). Gata4 was shown to be required for Hedgehog (Hh)-receiving progenitors within the second heart field (SHF) for normal OFT alignment. Restored cell proliferation in the SHF by knocking-down Pten failed to rescue OFT defects, suggesting that additional cell events under Gata4 regulation is important. SHF Hh-receiving cells failed to migrate properly into the proximal OFT cushion, which is associated with abnormal EMT and cell proliferation in Gata4 haploinsufficiency. The genetic interaction of Hh signaling and Gata4 is further demonstrated to be important for OFT development. Gata4 and Smo double heterozygotes displayed more severe OFT abnormalities including persistent truncus arteriosus (PTA). Restoration of Hedgehog signaling renormalized SHF cell proliferation and migration, and rescued OFT defects in Gata4 haploinsufficiency. In addition, there was enhanced Gata6 expression in the SHF of the Gata4 heterozygotes. The Gata4-responsive repressive sites were identified within 1kbp upstream of the transcription start site of Gata6 by both ChIP-qPCR and luciferase reporter assay. These results suggested a SHF regulatory network comprising of Gata4, Gata6 and Hh-signaling for OFT development.

Catheter ablation of ventricular arrhythmias originating from the junction of the pulmonary sinus cusp via a nonreversed U curve approach.

BACKGROUND: Ventricular arrhythmias (VAs) can originate from the pulmonary sinus cusp, and reversed U curve ablation has been highly efficient treatment. OBJECTIVE: The purpose of this study was to clarify the characteristics of VAs originating from the pulmonary sinus junction (PSJ): left cusp-anterior cusp (LC-AC), right cusp-left cusp (RC-LC), and right cusp-anterior cusp (RC-AC). METHODS: One hundred twenty-five consecutive patients with right ventricular outflow (RVOT)-type VAs were enrolled in the study and analyzed. RESULTS: Seventeen RVOT-type VAs (13.6%) had an anatomic origin at the PSJ (9 at LC-AC, 6 at RC-LC, 4 at RC-AC). For PSJ-VA patients, the earliest activation site was identified at the PSJ 22.65 ± 2.47 mm above the pulmonary sinus base and preceded QRS onset by 35.7 ± 12.7 ms (P <.001). Fourteen of the 17 PSJ-VA patients underwent successful ablation via a nonreversed U curve after failed reversed U curve ablation. The bipolar proximal potential was earlier, equal to, or later than the distal potential when the reversed U curve catheter tip was positioned at the bottom, middle, or junction region of individual sinus. Electrocardiographic analysis revealed a lower amplitude of RC-AC than LC-AC and RC-LC VAs (P <.001). CONCLUSION: The PSJ is a nonrare but distinct origin of RVOT-type VAs. The nonreversed U curve approach is a more feasible alternative for PSJ-VAs than the reversed U curve approach.

Differences in the extent of fibrosis in obstructive and nonobstructive hypertrophic cardiomyopathy.

AIMS: Left ventricular outflow tract (LVOT) obstruction is a key feature of hypertrophic cardiomyopathy (HCM) that identifies patients at increased risk of adverse outcomes. Previous studies have hypothesized that LVOT obstruction enhances myocardial fibrosis and increases left ventricular (LV) filling pressures, producing greater clinical deterioration. However, this hypothesis has not been demonstrated in a clinical cohort comparing obstructive and nonobstructive patients. METHODS: Patients with HCM in whom Doppler echocardiography was performed within 30 days of cardiac MRI were enrolled, using the E/e' ratio to assess LV diastolic function and late gadolinium enhancement to evaluate the extent of fibrosis. Data were assorted according to LVOT obstruction status at rest. RESULTS: The current study enrolled 67 patients who were mostly middle-aged (56.8 ±â€Š13.2 years old) men (75%) with preserved ejection fraction. Obstructive HCM presented a significant association with a high fibrosis extent [odds ratio (OR) 3.33; P = 0.034] which was maintained after adjusting for sex and age (OR 4.37; P = 0.016) but not for maximum LV wall thickness (OR 2.13; P = 0.225). Obstructive HCM was also associated with a clinically significant E/e' ratio more than 14 (OR 7.8; P = 0.001) which decreased slightly after adjusting for age, sex and maximum LV thickness (OR 6.54; P = 0.014). There was a significant association between an E/e' ratio more than 14 and the extent of fibrosis (OR 1.29; P < 0.001) which was maintained after adjusting for age, sex and maximum LV wall thickness (OR 1.36; P = 0.001). CONCLUSION: LVOT obstruction may play a role in the extent of fibrosis in HCM, possibly conditioning greater diastolic dysfunction.

Subdivision of the left ventricle by a discrete ridge and anomalous papillary muscle causing mid-ventricular obstruction: A case report.

A 16-year-old healthy boy visited our department because of a heart murmur. A 12-lead electrocardiogram showed left QRS axis deviation and repolarization abnormalities. Transthoracic echocardiography and a computed tomographic scan revealed a hypertrophied papillary muscle and a discrete ridge arising from the septal wall, causing mid-ventricular obstruction. Doppler echocardiography revealed that the pressure gradient at the obstruction was mild. The patient will be followed up annually, without medication or physical restriction.

Cardiac Magnetic Resonance for Diagnosis and Risk Stratification.

Cardiac MRI (CMR) is an essential tool for the evaluation of the patient with hypertrophic cardiomyopathy (HCM). First, the accurate morphologic imaging and measures that are possible with CMR help to ascertain the diagnosis. Second, the tissue characterization that can be done with MRI helps to define the abnormalities in the myocardium and to identify areas of fibrosis that have been linked to increase risk of sudden cardiac death and heart failure. In addition, CMR can help distinguish HCM from similar disease processes.

Sudden Cardiac Death Risk Stratification and the Role of the Implantable Cardiac Defibrillator.

Hypertrophic cardiomyopathy (HCM) is associated with an increased risk of sudden cardiac death (SCD), although perhaps not as significantly as previously believed. Given the heterogeneous nature of this disease entity, risk stratification of individuals with HCM remains challenging. The recent HCM risk-SCD prediction model seems to perform well in assessing individual SCD risk. Even though implantable cardiac defibrillators (ICDs) are effective in preventing SCD in patients at increased risk, the importance of shared decision making in deciding whether or not to undergo ICD implantation cannot be understated.

Clinical Spectrum and Management Implications of Left Ventricular Outflow Obstruction With Mild Ventricular Septal Thickness in Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HC) has historically been characterized as a disease of substantial left ventricular hypertrophy, often associated with dynamic left ventricular outflow tract obstruction. However, we have recently encountered patients with subaortic obstruction and only minimal basal septal thickness, raising important management implications. Thereby, we sought to characterize the natural history and treatment strategies for this under-recognized subgroup of HC patients with dynamic obstruction. Of 1,591 consecutive patients with a HC diagnosis, 113 (7%) were identified with outflow obstruction due to elongated mitral valve leaflets producing systolic anterior motion and septal contact typical of HC (gradient, 84 ± 29 mm Hg at rest or with exercise), with maximal ventricular septal thickness ≤15 mm, including 14 patients with only 10 to 12 mm. In addition to the mechanism of outflow obstruction, other evidence supporting a HC diagnosis prominently included: positive HC family history and/or pathogenic sarcomere mutation, arrhythmic sudden death event, typical histopathology of septal muscle, and characteristic mitral valve and papillary muscle anomalies. Over 3.8 ± 3.5 years, 41 patients (36%) developed severe heart failure including 36 who have undergone myectomy associated with reconstruction of the outflow tract and mitral valve apparatus, resulting in relief of gradient without iatrogenic ventricular septal defect or mitral valve replacement. Postoperatively, all 36 patients have survived with symptom relief to New York Heart Association classes I/II. In conclusion, these observations expand the HC clinical profile and phenotype to include an under-appreciated subgroup in which disease expression includes outflow obstruction due primarily to an elongated mitral valve, associated with only minimal (or normal) ventricular septal thickness. Such HC patients can develop marked functional limitation amenable to an operative strategy that effectively relieved symptoms due to outflow obstruction, but without mitral valve replacement.

Hypertrophic Cardiomyopathy in Liver Transplantation Patients.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is an autosomal dominant disorder that presents with a hypertrophied nondilated left ventricle. In the absence of other known causes of cardiomyopathy, it is often associated with left ventricular outflow tract obstruction during systole, systolic anterior motion of the mitral valve, mitral regurgitation, and increased risk of sudden cardiac death. When HCM coexists with end-stage liver disease, it can be further complicated by cirrhosis-associated cardiovascular abnormalities, including hyperdynamic circulation, systolic and diastolic dysfunction, and electrophysiologic abnormalities. METHODS: We retrospectively examined patient characteristics, comorbidities, preoperative echocardiogram results, sudden cardiac death risk prediction model score, and 1-year postoperative mortality of patients with HCM who underwent liver transplantation at our institution from January 1, 2000, through January 1, 2015. RESULTS: Of the 2,812 liver transplantations performed during the study period, we identified 15 patients with a preoperative diagnosis of HCM. When comparing the patients who did vs did not survive the first year after orthotopic liver transplantation, we identified significant differences in maximal left ventricular wall thickness (P = .004) and resting left ventricular outflow tract gradient (P = .004). Preoperative left atrium size (measured by echocardiography; P = .66) and the sudden cardiac death risk prediction model score (P = .32) were not significantly associated with 1-year survival. CONCLUSIONS: Preoperative left ventricular outflow tract gradient exceeding 60 mm Hg was strongly associated with death during the first year after transplant. These results suggest that the severity of HCM influences patient outcomes.

Surgery for Left Ventricular Outflow Tract Obstruction with a Relatively Thin Interventricular Septum.

BACKGROUND: To examine the results of myectomy and mitral valve surgery for systolic anterior motion (SAM) of the mitral valve and left ventricular outflow tract obstruction (LVOTO) with a relatively thin interventricular septum. METHODS: The subjects were 12 patients with SAM and LVOTO. Eight had hypertrophic obstructive cardiomyopathy (HOCM) with a mean interventricular septal thickness of 16 mm. Three had sigmoid septum and one had an unknown etiology. For HOCM, isolated extended myectomy was performed when mitral regurgitation was mild (n = 1) and extended myectomy plus mitral valve surgery was performed when mitral regurgitation was more than mild (n = 4) or primary valve etiologies existed (n = 3). Myectomy was performed for the three cases with sigmoid septum. Myectomy plus height reduction of the posterior mitral leaflet was performed for the one case with the unknown etiology of SAM. RESULTS: In the patients with HOCM, the maximum LVOT pressure gradient significantly decreased from 140 ± 18 to 16 ± 6 and 3 ± 3 mm Hg, while mitral regurgitation significantly decreased from 2.3 ± 0.5 to 0.5 ± 0.3 and 0.4 ± 0.2 at pre-op, early post-op, and last follow-up (3 ± 1 years), respectively. In the other etiologies, the maximum LVOT pressure gradient changed from 56 ± 15 to 25 ± 15 and 5 ± 4 mm Hg; mitral regurgitation changed from 2.0 ± 0.6 to 1.3 ± 0.3 and 1.3 ± 0.8, at pre-op, early post-op, and the last follow-up (3 ± 2 years), respectively. CONCLUSION: Myectomy with mitral valve surgery is an option for SAM and LVOTO in patients with a relatively thin interventricular septum.

Septal alcoholization in hypertrophic cardiomyopathy: about 11 cases.

Outcomes of septal alcoholization in hypertrophic obstructive cardiomyopathy are not enough studied in all centers. The purpose of this study was to determine the outcomes of septal alcoholization in hypertrophic obstructive cardiomyopathy in our hospital. A retrospective and prospective descriptive study focused on all patients aged at least 18 years treated by alcohol septal ablation between July 2005 and June 2010 in the cardiology unit of Clermont-Ferrand teaching Hospital. The inclusion criteria were, hypertrophic obstructive cardiomyopathy with left ventricular outflow tract obstruction ≥ 50 mmHg, symptomatic despite optimal medical therapy. The clinical, paraclinical data and the results of alcohol ablation were collected from medical records of patients and a telephone conversation with the patients or their physicians. These data were analyzed by EPI info 6.04. Eleven patients with average age of 56.27 ± 15, 83 were included of which 81.8% of men. The main indications of alcohol septal were dyspnea stage NYHA II-IV (45.5%), lipothymia (18.2%) and invalidating angina (18.2%). Main electrocardiographic abnormalities were left ventricular hypertrophy and disorders of repolarization with 72.7% each. Minor conductive disorders were found in 45.5% of the cases. The left ventricular outflow tract obstruction was 98.18 ± 25.93 mmHg before alcohol septal ablation and 18.91 ± 31.97 mmHg after a follow-up of 25.64 ± 21.97 months. The success rate was 81.8%. Conductive disorders (45.5%) required the establishment of a definitive pacemaker in 36.4% of the patients. A cardiac defibrillator was implanted at 27.3%. Septal alcoholization was succesful.

Recommendations on the Echocardiographic Assessment of Aortic Valve Stenosis: A Focused Update from the European Association of Cardiovascular Imaging and the American Society of Echocardiography.

Echocardiography is the key tool for the diagnosis and evaluation of aortic stenosis. Because clinical decision-making is based on the echocardiographic assessment of its severity, it is essential that standards are adopted to maintain accuracy and consistency across echocardiographic laboratories. Detailed recommendations for the echocardiographic assessment of valve stenosis were published by the European Association of Echocardiography and the American Society of Echocardiography in 2009. In the meantime, numerous new studies on aortic stenosis have been published with particular new insights into the difficult subgroup of low gradient aortic stenosis making an update of recommendations necessary. The document focuses in particular on the optimization of left ventricular outflow tract assessment, low flow, low gradient aortic stenosis with preserved ejection fraction, a new classification of aortic stenosis by gradient, flow and ejection fraction, and a grading algorithm for an integrated and stepwise approach of aortic stenosis assessment in clinical practice.

Isolated Subepicardial Right Ventricular Outflow Tract Scar in Athletes With Ventricular Tachycardia.

BACKGROUND: High-level endurance training has been associated with right ventricular pathological remodeling and ventricular tachycardia (VT). Although overlap with arrhythmogenic right ventricular cardiomyopathy (ARVC) has been suggested, the arrhythmogenic substrate for VTs in athletes is unknown. OBJECTIVES: The goal of this study was to evaluate whether electroanatomic scar patterns related to sustained VT can distinguish exercise-induced arrhythmogenic remodeling from ARVC and post-inflammatory cardiomyopathies. METHODS: In 57 consecutive patients (mean age 48 ± 16 years; 83% male) undergoing catheter ablation for scar-related right ventricular VT, 2 distinct scar distributions were identified: 1) scars involving the subtricuspid right ventricle in 46 patients (group A); and 2) scars restricted to the anterior subepicardial right ventricular outflow tract in 11 patients (group B). RESULTS: Definite ARVC or post-inflammatory cardiomyopathy was diagnosed in 40 (87%) of 46 group A patients but was not diagnosed in any patients in group B. All group B patients underwent intensive endurance training for a median of 15 h/week (interquartile range [IQR]: 10 to 20 h/week) for a median of 13 years (IQR: 10 to 18 years). The cycle lengths of scar-related VTs were significantly faster in group B patients (257 ± 34 ms vs. 328 ± 72 ms in group A; p = 0.003). Catheter ablation resulted in complete procedural success in 10 (91%) of 11 group B patients compared with 26 (57%) of 46 group A patients (p = 0.034). During a median follow-up of 27 months (IQR: 6 to 62 months), 50% of group A patients but none of the group B patients had a VT recurrence. CONCLUSIONS: This study describes a novel clinical entity of an isolated subepicardial right ventricular outflow tract scar serving as a substrate for fast VT in high-level endurance athletes that can be successfully treated by ablation. This scar pattern may allow distinguishing exercise-induced arrhythmogenic remodeling from ARVC and post-inflammatory cardiomyopathy.

Balloon Versus Computed Tomography Sizing of the Aortic Annulus for Transcatheter Aortic Valve Replacement and the Impact of Left Ventricular Outflow Tract Calcification and Morphology on Sizing.

OBJECTIVES: To evaluate the role of balloon annular sizing in transcatheter aortic valve replacement (TAVR). BACKGROUND: Multidetector cardiac computed tomography (MDCT) is the gold standard for aortic annular sizing in TAVR. Balloon sizing is increasingly used in patients with borderline annular size and severe calcification. A comparison between these two techniques is needed. METHODS: We retrospectively compared baseline characteristics and 30-day outcomes of patients undergoing balloon-expandable TAVR using annular MDCT or balloon sizing. Paravalvular leak (PVL) rates were compared adjusting for access site, valve generation, size, and valve calcification. RESULTS: A total of 205 patients underwent TAVR with MDCT (n = 110) or balloon sizing (n = 95). Balloon-sized patients were older (83 years vs 81 years; P=.03), had more valve calcification (60.2% vs 30.9%; P<.001), and underwent more minimalist TAVR (61.1% vs 40%; P=.03). Although we found no difference between balloon and MDCT sizing in rates of acute renal failure (3.2% vs 0.9%; P=.34), annular rupture (1.1% vs 1.8%; P>.99), ≥ mild PVL by angiography (40% vs 35.5%; P=.57), or 30-day transthoracic echocardiography (40.7% vs 29.3%; P=.78), balloon-sized patients had a higher aortic regurgitation index (≥25) of 74.4% vs 54.1% (P=.01). Thirty-day rates of ≥ moderate PVL were 7.0% with balloon and 5.7% with MDCT sizing (P=.34). Balloon sizing recommended a different valve size in 34.0% of patients who underwent both methods (n = 50). A different recommendation occurred more often in patients with moderate/severe annular calcification (50.0% vs 33.3%; P=.01) and non-tubular left ventricular outflow tracts (LVOTs) (70.6% vs 30.3%; P=.01). CONCLUSION: Balloon sizing can be a complement to MDCT for annular sizing in TAVR, especially in patients with moderate/severe annular calcification, borderline annular size, and non-tubular LVOT.