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Aims: Cardiac implantable electronic device (CIED) therapy is fundamental to the management of LMNA cardiomyopathy due to the high frequency of atrioventricular block and ventricular tachyarrhythmias. We aimed to define the role of cardiac resynchronization therapy (CRT) in impacting heart failure in LMNA cardiomyopathy. Methods and results: From nine referral centres, LMNA cardiomyopathy patients who underwent CRT with available pre- and post-echocardiograms were identified retrospectively. Factors associated with CRT response were identified (defined as improvement in left ventricular ejection fraction [LVEF] ≥5% 6 months post-implant) and the associated impact on the primary outcome of death, implantation of a left ventricular assist device or cardiac transplantation was assessed. We identified 105 patients (mean age 51 ± 10 years) undergoing CRT, including 70 (67%) who underwent CRT as a CIED upgrade. The mean change in LVEF ∼6 months post-CRT was +4 ± 9%. A CRT response occurred in 40 (38%) patients and was associated with lower baseline LVEF or a high percentage of right ventricular pacing prior to CRT in patients with pre-existing CIED. In patients with a European Society of Cardiology class I guideline indication for CRT, response rates were 61%. A CRT response was evident at thresholds of LVEF ≤45% or percent pacing ≥50%. There was a 1.3 year estimated median difference in event-free survival in those who responded to CRT (p = 0.04). Conclusion: Systolic function improves in patients with LMNA cardiomyopathy who undergo CRT, especially with strong guideline indications for implantation. Post-CRT improvements in LVEF are associated with survival benefits in this population with otherwise limited options.

The successful performance of experiments is tightly related to the efficiency and reliability of the analytical methods used for the data analysis. This is particularly true when data is collected as images and the quantification of the biological effect behind the picture is often an issue. Consistent evaluation represents a challenge even for experienced biologists. Even though other techniques allow the quantification of fluorescent cell populations, (FACS, among others) image analysis is widely used. For this reason there is an increasing need of methods for reliable and reproducible quantification of images. To this aim a new algorithm for image analysis has been developed that allows rapid quantification of fluorescent Dual Reporter cells populations. These cells can express RFP (αSMA) or EGFP (collagen), and, via epi-fluorescence, come up as red or green, or yellow when RFP and GFP co-localize within the same cell. The algorithm can quantify and classify these sub-sets, by using a fuzzy, two-pass class partitioning, in addition to Difference of Gaussians and watershed segmentation techniques for blob detection and extraction. Results show average errors in the 2-6% range and an analysis time of 6-9 seconds per acquired image. The algorithm was validated against manual quantification techniques and compared to other state-of-the-art software. It allows rapid detection and extraction of Dual Reporter cells distributions in acquired epi-fluorescence optical fields. Finally, thanks to the implementation of semi-automated calibration procedures, the algorithm constitutes a totally objective instrument for quantification and classification measurements, especially when class boundaries are not sharply defined.

BACKGROUND: In dilated cardiomyopathy (DCM), the clinical and prognostic implications of rare variants in sarcomeric genes remain poorly understood. To address this question, we analyzed the outcome of rare sarcomeric gene variants in patients enrolled in our Familial Cardiomyopathy Registry. METHODS: DCM families harboring rare sarcomeric variants in MYH6, MYH7, MYBPC3, TNNT2, and TTN were identified. Genotype-phenotype association analysis was performed, and long-term survival-free from death or heart transplant was compared between carriers and noncarriers. RESULTS: We found 24 rare variants (3 in MYH6, 3 in MYH7, 3 in MYBPC3, 2 in TNNT2, and 13 in TTN) affecting 52 subjects in 25 families. The phenotypes of variant carriers were severe (3 sudden deaths, 6 heart failure deaths, 8 heart transplants, 2 ventricular fibrillations). There was no difference in the overall long-term survival between carriers and the 33 noncarriers (p = 0.322). However after 50 years of age, the combined endpoint of death or transplant was decreased in carriers as compared to noncarriers (p = 0.026). CONCLUSIONS: Patients with DCM carrying rare variants in sarcomeric genes manifest a poorer prognosis as compared to noncarriers after the age of 50 years. These data further support the role of genetic testing in DCM for risk stratification.

We present the case of PRKAG2 cardiac syndrome, a rare autosomal-dominant genetic disease characterized by peculiar clinical and electrophysiological abnormalities. We clearly show through the images the peculiar clinical features that should raise suspicion of a mutant PRKAG2 gene. Indeed, together with an accurate clinical and instrumental evaluation, genetic analysis can contribute to a correct diagnosis in order to promptly treat and prevent the complications of the disease.

Scaffolds for tissue engineering can be either natural or synthetic materials. The latter allow control of chemical, physical and mechanical properties and also provide support and shape, however they are not of biological origin, and therefore could not promote cell adhesion. This problem does not occur in natural materials however, they have the drawback of having non-suitable mechanical properties and tend to deteriorate too fast. In this work we study the influence of different substrate on the metabolic as well as proliferative cells activity. In particular 4 substrates have been considered: (i) medical grade StageFlexer (silicone elastomer), (ii) Polydimethylsiloxane (PDMS), (iii) PDMS with a layer of carbon nanotubes (CNT’s) and (iv) PDMS with a layer of ceramic whiskers. The results of both tests (metabolic and proliferative capacity) showed that the PDMS without any surface treatment, is the worst of the tested substrates. The reason is to be found in the fact that the PDMS is highly hydrophobic and therefore cells have low adhesion to the substrate. This represents a major limitation of PDMS and its functionalization is necessary to improve cell adhesion. Cells placed on PDMS samples with CNT’s show higher metabolic activity and proliferative capacity, compared to the PDMS and PDMS treated with fibronectin. However, the best outcomes have occurred with the PDMS substrate coated with ceramic whiskers.

Thymopoietin or TMPO (indicated by its alternative gene symbol, LAP2, in this work) has been proposed as a candidate disease gene for dilated cardiomyopathy (DCM), since a LAP2 product associates with nucleoplasmic lamins A/C, which are encoded by the DCM gene LMNA. We developed a study to screen for genetic mutations in LAP2 in a large collection of DCM patients and families. A total of 113 subjects from 88 families (56 with familial DCM (FDC) and 32 with sporadic DCM) were screened for LAP2 mutations using denaturing high-performance liquid chromatography and sequence analysis. We found a single putative mutation affecting the LAP2α isoform in one FDC pedigree. The mutation predicts an Arg690Cys substitution (c.2068C>T; p.R690C) located in the C-terminal domain of the LAP2α protein, a region that is known to interact with lamin A/C. RT-PCR, Western blot analyses, and immunolocalization revealed low-level LAP2α expression in adult cardiac muscle, and localization to a subset of nuclei. Mutated Arg690Cys LAP2α expressed in HeLa cells localized to the nucleoplasm like wild-type LAP2α, with no effect on peripheral and nucleoplasmic lamin A distribution. However, the in vitro interaction of mutated LAP2α with the pre-lamin A C-terminus was significantly compromised compared to the wild-type protein. LAP2 mutations may represent a rare cause of DCM. The Arg690Cys mutation altered the observed LAP2α interaction with A-type lamins. Our finding implicates a novel nuclear lamina-associated protein in the pathogenesis of genetic forms of dilated cardiomyopathy. Hum Mutat 26(6), 566–574, 2005. © 2005 Wiley-Liss, Inc.

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X-linked dilated cardiomyopathy (XLDC) is a familial heart disease presenting in young males as a rapidly progressive congestive heart failure, without clinical signs of skeletal myopathy. This condition has recently been linked to the dystrophin gene in some families and deletions encompassing the genomic region coding for the first muscle exon have been detected. In order to identify the defect responsible for this disease at the molecular level and to understand the reasons for the selective heart involvement, a family with a severe form of XLDC was studied. In the affected members, no deletions of the dystrophin gene were observed. Analysis of the muscle promoter, first exon and intron regions revealed the presence of a single point mutation at the first exon-intron boundary, inactivating the universally conserved 5' splice site consensus sequence of the first intron. This mutation introduced a new restriction site for Msel, which cosegregates with the disease in the analyzed family. Expression of the major dystrophin mRNA isoforms (from the muscle-, brain- and Purkinje cell-promoters) was completely abolished in the myocardium, while the brain- and Purkinje cell- (but not the muscle-) isoforms were detectable in the skeletal muscle. Immunocytochemical studies with anti-dystrophin antibodies showed that the protein was reduced in quantity but normally distributed in the skeletal muscle, while it was undetectable in the cardiac muscle. These findings indicate that expression of the muscle dystrophin isoform is critical for myocardial function and suggest that selective heart involvement in dystrophin-linked dilated cardiomyopathy is related to the absence, in the heart, of a compensatory expression of dystrophin from alternative promoters.

Recent studies have demonstrated that genetic factors are likely to play a major role in the pathogenesis of idiopathic dilated cardiomyopathy (IDC). In clinical surveys, a familial trait has been demonstrated in 20 to 30\% of idiopathic dilated cardiomyopathy patients (familial dilated cardiomyopathy). Molecular genetic studies have confirmed the clinical hypothesis of genetic heterogeneity in familial dilated cardiomyopathy, and are currently producing relevant advances in the understanding of this disease. The autosomal dominant form is considered to be the most frequent form of inherited idiopathic dilated cardiomyopathy. After the exclusion of a large series of candidate genes, the first familial dilated cardiomyopathy gene has been mapped to the long arm of chromosome 9. A second locus has been found on chromosome 1. Moreover, in two large families, characterized by a peculiar form of conduction delays and later development of myocardial dysfunction, the disease loci have been mapped to chromosome 1 and 3, respectively. The identification of the disease genes is in progress. In families with X-linked dilated cardiomyopathy, the disease gene has been identified as the dystrophin gene. The 5' end of the gene appears to be the critical region for the development of dilated cardiomyopathy without clinical evidence of muscle dystrophy. Furthermore, other cytoskeletal proteins, such as adhalin, could be involved in the pathogenesis of familial dilated cardiomyopathy. In familial right ventricular cardiomyopathy (or arrhythmogenic right ventricular dysplasia) characterized by isolated or prevalent right ventricular involvement, three different disease loci have been identified so far: two localized on the long arm of chromosome 14 and one on chromosome 1. The disease genes are still unknown and are currently under investigation. The study of the genetic factors at the molecular level is starting to elucidate the pathogenetic mechanisms of idiopathic dilated cardiomyopathy. These findings will also have relevant clinical and therapeutic implications.

In a prospective study on 340 cases with primary myocardial disease, eight patients (six males, two females, mean age 36 years, range 24-47) with an idiopathic left ventricular aneurysm were observed. All patients had normal coronary arteries, no angina or history of myocardial infarction; all but one had no risk factors for ischaemic heart disease; all had normal right ventricles; one patient had a history of familial dilated cardiomyopathy, two of 'flu-like' syndrome at the time of first symptom and two of alcohol abuse. All patients had ventricular tachycardia (VT), five sustained (of right bundle branch block morphology in three, and of different morphologies in two), three non-sustained. Patients with sustained VT had inducible VT (resembling the clinical one) on electrophysiological study. Electrocardiogram (ECG) showed an infarction pattern in three cases. Aneurysms were of limited size (2.1 +/- 1/11 segments on echocardiography) and were located in the septum, apex or posterior wall. Left ventricular ejection fraction (LVEF) was reduced (0.50) in six patients and was not correlated with the aneurysm size. The duration of illness was inversely correlated with LVEF (P0.05). Endomyocardial biopsy showed evidence of diffuse pathological changes in all cases (cell hypertrophy, myofibrillar lysis, mitochondriosis). During follow-up (64 +/- 32 months), patients were successfully treated with anti-arrhythmic drugs: no patients required surgical treatment to control ventricular arrhythmia. Considering the clinical and pathological features of idiopathic left ventricular aneurysm, this primary myocardial disease could be classified as a novel peculiar form of cardiomyopathy.