[show abstract][hide abstract] ABSTRACT: BACKGROUND: Left ventricular noncompaction (LVNC) is a myocardial disorder characterized by excessive left ventricular (LV) trabeculae. Current methods for quantification of LV trabeculae have limitations. The aim of this study is to describe a novel technique for quantifying LV trabeculation using cardiovascular magnetic resonance (CMR) and fractal geometry. Observing that trabeculae appear complex and irregular, we hypothesize that measuring the fractal dimension (FD) of the endocardial border provides a quantitative parameter that can be used to distinguish normal from abnormal trabecular patterns. METHODS: Fractal analysis is a method of quantifying complex geometric patterns in biological structures. The resulting FD is a unitless measure index of how completely the object fills space. FD increases with increased structural complexity. LV FD was measured using a box-counting method on CMR short-axis cine stacks. Three groups were studied: LVNC (defined by Jenni criteria), n=30(age 41+/-13; men, 16); healthy whites, n=75(age, 46+/-16; men, 36); healthy blacks, n=30(age, 40+/-11; men, 15). RESULTS: In healthy volunteers FD varied in a characteristic pattern from base to apex along the LV. This pattern was altered in LVNC where apical FD were abnormally elevated. In healthy volunteers, blacks had higher FD than whites in the apical third of the LV (maximal apical FD: 1.253+/-0.005 vs. 1.235+/-0.004, p<0.01)(mean+/-s.e.m.). Comparing LVNC with healthy volunteers, maximal apical FD was higher in LVNC (1.392+/-0.010, p<0.00001). The fractal method was more accurate and reproducible (ICC, 0.97 and 0.96 for intra and inter-observer readings) than two other CMR criteria for LVNC (Petersen and Jacquier). CONCLUSIONS: FD is higher in LVNC patients compared to healthy volunteers and is higher in healthy blacks than in whites. Fractal analysis provides a quantitative measure of trabeculation and has high reproducibility and accuracy for LVNC diagnosis when compared to current CMR criteria.
Journal of Cardiovascular Magnetic Resonance 05/2013; 15(1):36. · 4.44 Impact Factor
[show abstract][hide abstract] ABSTRACT: BACKGROUND: -Anderson Fabry disease (AFD) is a rare but under-diagnosed intracellular lipid disorder which can cause left ventricular hypertrophy (LVH). Lipid is known to shorten the MRI parameter T1. We hypothesised that non-contrast T1 mapping by cardiovascular magnetic resonance would provide a novel and useful measure in this disease with potential to detect early cardiac involvement and distinguish AFD LVH from other causes. METHODS AND RESULTS: -227 subjects were studied: AFD patients (n=44, 55% with LVH), healthy volunteers (n=67, 0% with LVH), hypertension (n=41, 24% with LVH), hypertrophic cardiomyopathy (n=34, 100% with LVH), severe aortic stenosis (n=21, 81% with LVH) and definite AL cardiac amyloidosis (n=20, 100% with LVH). T1 mapping was performed using the Sh-MOLLI sequence on a 1.5T magnet before gadolinium administration with primary results derived from the basal and mid septum. Compared to health volunteers, septal T1 was lower in AFD and higher in other diseases (AFD vs healthy volunteers vs other patients, 882±47ms, 968±32ms, 1018±74ms, P<0.0001). In patients with LVH (n=105), T1 discriminated completely between AFD and other diseases with no overlap. In AFD, T1 correlated inversely with wall thickness (R=-0.51, P=0.0004) and was abnormal in 40% of subjects who did not have LVH. Segmentally, AFD showed pseudo-normalisation or elevation of T1 in the LV infero-lateral wall, correlating with the presence or absence of late gadolinium enhancement (1001±82ms vs 891±38ms, P<0.0001) CONCLUSIONS: -Non-contrast T1 mapping shows potential as a unique and powerful measurement in the imaging assessment of left ventricular hypertrophy and Anderson Fabry disease.
[show abstract][hide abstract] ABSTRACT: A spongiform epidemic is upon us - myocardial trabeculae are everywhere as left ventricular noncompaction (LVNC) ingratiates itself into modern day cardiology. Current understanding of the condition is evolving but remains incomplete, and brings to mind the chronicles of another great cardiac story: mitral valve prolapse. Anecdote suggests that many individuals with prominent trabeculae may be being falsely labelled with a disease - LVNC - using poor echocardiographic and cardiovascular magnetic resonance criteria. Until we have robust diagnostic criteria, aetiology, clinicopathological significance and prognosis, the risk of casualties from ascertainment bias will remain. We should look to history and learn from past mistakes - specifically from the mitral valve prolapse story to show the way forward for LVNC. Meanwhile, clinicians (and patients) should be wary, bearing in mind the possibility that they might be seeing LVNNC - left ventricular non-noncompaction.
International journal of cardiology 05/2012; · 7.08 Impact Factor
[show abstract][hide abstract] ABSTRACT: In reply to the letter by Finsterer and Stöllberger entitled "Consensus on unsolved issues of hypertrabeculation/noncompaction is warranted," the authors reaffirm the need for a concordant opinion on the unsolved issues which still loom over the diagnostic and clinical facets of left ventricular non-compaction. Subjects known to have ventricular hypertrabeculation and who subsequently experience a thromboembolic event should still be meticulously screened for other commoner and possibly co-existent embolic sources. In the absence of systolic dysfunction left ventricular non-compaction alone is not an indication for oral anticoagulation in so far as the primary prevention for thromboembolism is concerned. There exists no exact proof that the degree of inotropic dysfunction in hypertrabeculated hearts is directly and solely related to the extent of the non-compaction. Subendocardial perfusion deficits; diminished coronary blood flow reserve; trabecular fibrosis and aberrations at the cellular level may also be responsible for affecting ventricular systolic function. Early neurological referral is indicated following the diagnosis of non-compaction with the aim of screening for the many disorders known to be associated with this condition and genetic screening tests are best resorted to only if clinical examination fails to expose a relevant syndrome. The current cardiac magnetic resonance diagnostic criteria for non-compaction still have some important limitations which beckon a unifying consensus.
International journal of cardiology 12/2009; · 7.08 Impact Factor
[show abstract][hide abstract] ABSTRACT: Left ventricular non-compaction (LVNC) is a rare disorder that results in multiple deep trabeculations within the left ventricular myocardium. It is thought to be due in part, to an arrest of myocardial development but more recent evidence suggests that some cases may actually be acquired while other isolated cases have regressed with time. Transthoracic echocardiography remains the imaging modality of choice for LVNC where diagnosis is based on the identification of multiple prominent ventricular trabeculations with intertrabecular spaces communicating with the ventricular cavity. There is a broad and potentially confusing spectrum of clinical symptomatology in patients with ventricular non-compaction meaning that the primary diagnosis is often missed. Complications such as potentially malignant arrhythmias, left ventricular failure, and cardioembolic events arising as a result of non-compaction must be treated in an attempt to decrease morbidity and mortality from this disorder. The ultimate outcome for patients remains unclear with some boasting a prolonged asymptomatic course, to others displaying a rapid deterioration of left ventricular systolic function, leading to heart transplantation or death. In conclusion, LVNC while remaining a rare cardiomyopathy, shall probably be diagnosed with increasing frequency in the coming years because of heightened awareness about its natural history and clinical manifestations and because of the improved modalities available for cardiac imaging.
International journal of cardiology 09/2009; 140(2):145-53. · 7.08 Impact Factor