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The 12-lead resting electrocardiogram (ECG) showing normal sinus rhythm and a broad QRS duration of 146 ms with a left bundle branch block (LBBB) morphology and a normal QT interval.
Source publication
Left ventricular non-compaction (LVNC) is a genetic cardiomyopathy often familial and autosomal dominant. It is characterized by morphological abnormalities affecting the left ventricular myocardium with prominent trabeculations of the inner surface of the ventricle, often extending deep into the ventricular wall. There are no pathognomonic histolo...
Context in source publication
Context 1
... and a broad QRS duration of 146 ms with a left bundle branch block (LBBB) morphology ( Figure 1). B-Type natriuretic peptide (BNP) was elevated at 386 pmol/l (upper limit of normal being 4 pmol/l). A repeat transthoracic echocardiogram confirmed severe biventricular impairment (LV end diastolic dimension 5.9 cm, end systolic dimension 5.0 cm LVEF 15% and right ventricular dilatation; inlet dimensions 4.3 cm, mid cavity 4.8 cm). Additionally the LV was heavily trabeculated, particularly at the lateral, anterior and apical segments, suggestive of left ventricular non-compaction (Figure 2). A cardiac magnetic resonance (CMR) scan with Gadolinium (Gd) contrast was performed, which was also highly suggestive of LV noncompaction in the setting of severe biventricular systolic dysfunction and dilatation. Early Gd enhancement demonstrated a left atrial appendage thrombus and the delayed phase showed diffuse uptake in the non-compacted layers (See Figures 3–5). Despite maximally tolerated pharmacological therapy for heart failure, she remained in New York Heart Association (NYHA) functional class III. Hence, she fulfilled current guidelines for the implantation of cardiac resynchronisation therapy (LVEF <35%, QRS duration >120 ms, Optimal Tolerated Medical Therapy) (Figure 6), 5 which was performed. Device implantation led to marked improvement in the patient’s symptomatic status (NYHA functional class II) and facilitated uptitration of the patient’s heart failure medication following discharge. One month post discharge, repeat TTE showed improvement in LVEF and LV dimensions (LVEF, 40%; left ventricular end diastolic diameter (LVEDD), 5.2 cm; left ventricular end systolic diameter (LVESD), 4.1 cm) and the BNP level had reduced to 13 pmol/l. This correlated with further recovery in her clinical status with a resolution of her heart failure symptoms (NYHA class I) and reduction in oral loop diuretic requirements. This case of LVNC highlights the potential cardiac and extracardiac complications of this genetic cardiomyopathic process. It illustrates the need for multimodal cardiac imaging. The case demonstrates the complex management of this condition with particular focus on anticoagulation and heart failure management including cardiac resynchronization therapy. K.H., R.S. and T.A.T. were involved in the preparation of the manuscript and accompanying images; A.M.D., I.R., S.K.P. and T.A.M. were involved in analysis and manuscript preparation; and C.B. pro- vided critical review of the manuscript. All authors read and approved the final ...
Citations
... The severity of these types of defects ranges from simple defects with no symptoms at birth, such as a small atrial septal defect (ASD), to complicated defects that are life-threatening and require intervention, such as Tetralogy of Fallot (TOF) [3,4]. One particular defect known as left ventricular noncompaction (LVNC) or "spongy myocardium" has no treatment at present, with the major therapy being heart failure and anticoagulation medications [5]. LVNC is classified as a rare genetic cardiomyopathy, occurring in 0.01% to 0.27% of the population, characterized by arrest of normal myocardium development, leading to a thin compact myocardial layer and an extensive non-compacted trabecular network [6,7]. ...
... LVNC is classified as a rare genetic cardiomyopathy, occurring in 0.01% to 0.27% of the population, characterized by arrest of normal myocardium development, leading to a thin compact myocardial layer and an extensive non-compacted trabecular network [6,7]. Noncompaction of the ventricular myocardium can increase the risk of cardiac embolism, atrial fibrillation, ventricular arrhythmia and heart failure [5,7]. Although this defect occurs mostly in the LV, right ventricular (RV) noncompaction has also been reported in less than one-half of LVNC patients [8,9]. ...
... Phospho-histone H3 (pHH3) immunostaining to mark proliferating cells undergoing mitosis in ventricular myocardium (myo) of E9.5 Rac1 Nkx2. 5 and Rac1 f/f hearts (A,B). Proliferation rate was significantly decreased in E9.5 Rac1 Nkx2.5 ventricular myocardium compared to littermate controls (C). ...
Background:
Left ventricular noncompaction (LVNC) is a cardiomyopathy that can lead to arrhythmias, embolic events and heart failure. Despite our current knowledge of cardiac development, the mechanisms underlying noncompaction of the ventricular myocardium are still poorly understood. The small GTPase Rac1 acts as a crucial regulator of numerous developmental events. The present study aimed to investigate the cardiomyocyte specific role of Rac1 in embryonic heart development.
Methods and results:
The Nkx2.5-Cre transgenic mice were crossed with Rac1f/f mice to generate mice with a cardiomyocyte specific deletion of Rac1 (Rac1Nkx2.5) during heart development. Embryonic Rac1Nkx2.5 hearts at E12.5-E18.5 were collected for histological analysis. Overall, Rac1Nkx2.5 hearts displayed a bifid apex, along with hypertrabeculation and a thin compact myocardium. Rac1Nkx2.5 hearts also exhibited ventricular septal defects (VSDs) and double outlet right ventricle (DORV) or overriding aorta. Cardiomyocytes had a rounded morphology and were highly disorganized, and the myocardial expression of Scrib, a planar cell polarity protein, was reduced in Rac1Nkx2.5 hearts. In addition, cell proliferation rate was significantly decreased in the Rac1Nkx2.5 ventricular myocardium at E9.5.
Conclusions:
Rac1 deficiency in the myocardium impairs cardiomyocyte elongation and organization, and proliferative growth of the heart. A spectrum of CHDs arises in Rac1Nkx2.5 hearts, implicating Rac1 signaling in the ventricular myocardium as a crucial regulator of OFT alignment, along with compact myocardium growth and development.
: This is a systematic review of current evidence regarding the efficacy of cardiac resynchronization therapy (CRT) on patients with dilated cardiomyopathy and isolated left ventricular noncompaction (IVNC). This systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. Records were searched in Pubmed, Cochrane Library, Google Scholar, Biomed Central. We included only studies focused on ventricular noncompaction patients treated with CRT. Of 46 records screened, we included 14 studies involving a total of 70 patients. All studies showed a reduction of New York Heart Association class and an increase of the ejection fraction that ranges from 8 to 36% at follow-up after CRT. Analyzing the type of response to CRT, approximately 50% of the patients were classified as responders to the therapy and most of them were super-responders. In conclusion, CRT provides beneficial effects in terms of clinical status and left ventricular function on IVNC patients with heart failure. CRT responders seem to have a great left ventricular reverse remodeling supporting the theory that CRT is able to provide an additional benefit in the IVNC disease, improving the performance of IVNC segments, when paced.
