Diagnostic utility of genetic testing in restrictive cardiomyopathy a single refferal centre experience

Introduction

Restrictive cardiomyopathy (RCM) is considered to have a genetic background in approximately 50–60% of patients (pts) [1,2,3].

Purpose

The aim of the study was to assess the frequency of pathogenic gene variants in Polish patients with RCM.

Methods

Restrictive cardiomyopathy was diagnosed by transthoracic echocardiography. The analysis included all consecutive unrelated pts with RCM admitted to the cardiology department from January 2015 to December 2016. Light-chain (AL) amyloidosis was diagnosed using tissue biopsy, concentration of serum free light chains and bone marrow biopsy. A genetic test was offered to every patient without AL amyloidosis. In 4 pts coding regions of TTR or GLA genes were screened by Sanger sequencing. Next Generation Sequencing (NGS) was performed: a panel covering coding regions of >4800 disease-associated genes in 18 pts and Whole Exome Sequencing (WES) in 2 pts. Classification of rare variants was made according to ACMG criteria [4].

Results

Forty-four pts were enrolled. Eighteen pts were diagnosed with AL amyloidosis. One patient was diagnosed with histologically-proven myocarditis and one patient with transthyretin (ATTR) amyloidosis declined genetic test. The other 24 pts (median age 48 yrs, 6 males) underwent genetic testing, their median values (interquartile ranges) of the following parameters were: NT-proBNP, 2508 (995–5895) pg/mL; hs-TnT, 25 (18–46) ng/L; E/A ratio, 2.5 (1.8–4.5); E wave deceleration time, 135 (98–167) ms; E/e' ratio, 16 (12–19); left ventricular (LV) posterior wall, 13 (12–14.5) mm; interventricular septum, 14 (13–17) mm and LV end-diastolic dimension, 48 (43–49) mm. Pathogenic or likely pathogenic variants were detected in 16 probands: 5 in MYH7 gene, 3 in TNNI3 gene, 2 in MYBPC3 gene, 1 in BAG3 gene, 1 in PRAKG2 gene, 2 in GLA gene and 2 in TTR gene.

Conclusions

Genetic testing is justified in every patient with RCM, in whom AL amyloidosis is excluded. The molecular diagnosis in RCM may result in causal treatment of Anderson-Fabry disease and ATTR amyloidosis or improve disease management in other types of RCM. MYH7 gene is the most common causative gene in Polish patients with RCM.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): National Institute of Cardiology

What do clinicians think of the anatomical knowledge of medical students? Results of a survey

Human anatomy is one of basic courses in medical education. It usually takes place during the first year of the medical school syllabus. However, the results of the course, if defined as profound anatomical knowledge, are not applied by the students until several years after the final anatomy examination. The aim of the study was to evaluate the anatomical knowledge of senior medical students. For this reason a survey was distributed among teachers responsible for clinical rotas. The results of the study were intended to give the answer to the question, "What do students remember several years after the anatomy examination?" as expressed by their clinical teachers. The questionnaire included four closed questions and one open question. The closed questions concerned general anatomical knowledge, whether the anatomy course should be extended and whether additional courses should be introduced and included a question about student knowledge of particular systems. The open question concerned ways of improving anatomical education. As a result of the survey it was observed that surgical specialists had a significantly lower opinion of the medical knowledge of their students than had medical specialists. Most of the suggestions for improving anatomical education were related to introducing clinical applications of anatomical knowledge.

Histologic evaluation of the atrioventricular nodal artery in healthy humans and in patients with conduction disturbances

The anatomy of the conduction system of the heart so relevant in the contemporary invasive cardiology is not fully understood. It has turned out that ablation procedures bring new information as to its structure and function, but in some cases can result in complete a-v block. Atrioventricular nodal artery located within the nodal-perinodal tissue can probably be damaged during the ablation procedures. Therefore, we decided to explore in detail the morphology and the topography of the atrioventricular nodal artery in healthy humans and in patients with clinical traits of a-v conduction disturbances requiring permanent pacing. The microscopic study was carried out on 30 normal human hearts specimens (17 F, 3 M) from 17 to 86 years of age, and on 20 hearts with conduction disturbances (11 F, 9 M) from 39 to 85 years of age. We found that the number of the atrioventricular node arteries is different and independent of the extent that induces block causing conduction disturbances. The topography of the artery in perinodal zone was consistent in normal hearts, yet in hearts with conduction disturbances we observed about 2% of deviations in its location. It might be the reason for generation of iatrogenic complications after invasive cardiological procedures. The morphology revealed changes in 50% of the examined hearts and their vessel walls, which was declared to be connected with ageing. This correlated with certain stages of atherosclerosis as well as hypertension characteristic of elderly patients. We observed that in 33% of hearts from control group small parietal thrombi were detected and in 60% of paced group respectively. Hence, it seems that the procedures in perinodal zone should be performed in its proximal part because of a minor probability of direct and indirect (through nodal artery) damage of the atrioventricular structure of the junction.

The morphological conditions of the permanent pacemaker lead extraction

Pacemaker lead extraction is the treatment of choice in infectious complications regarding implantation procedure. The purpose of this study was to estimate the safety of the extraction in relation to the morphological changes of the pacing electrode. Research was carried out on materials consisting of 60 human hearts from 45 to 95 years of age (average 63 +/- 15 yrs), with VVI or DDD pacing (pacing duration 84 +/- 26 months) fixed in a formalin solution. Classical macroscopic anatomical methods were applied. In 44 hearts (73.3%) from the investigated group the posterior tricuspid leaflet was thickened only, and in 24 of these hearts the process regarded not only posterior leaflet but also the septal one and especially commissure between them. In 52 hearts (86.6%) inflammatory reaction spread also to the neighbouring part of the electrode. The length of the neointima-inflammatory tissue ranged from 4 to 8 mm (average 5 +/- 2 mm). On the tip of the electrode in the right ventricle cavity in 56 hearts (93.3%) we observed that endocardial leads were surrounded by fibrous thickening, and partially covered by endocardial tissue. We concluded that from the anatomical point of view the extraction of the pacing electrode seems to be questionable, especially in long-term permanent pacing. The experimental traction shows that only recently implanted electrodes were removed without any complications and in others with fraction of the tip, myocardial tissue avulsion or such removal was not successful at all.

The presence of Chlamydia pneumoniae in atherosclerotic plaques--a report of three cases of ischaemic heart disease

The report presents three cases of ischaemic heart disease in which Chlamydia pneumoniae infections were detected first serologically, later the bacteria were shown in atherosclerotic plaques with electron microscopy, and finally C. pneumoniae strains were isolated from the tissues.

Light and electron microscopic picture of atherosclerotic plaque in stable and unstable angina

By presenting this series of 127 cases of coronary atherectomy the authors join the workers who study morphological differences between the atherosclerotic plaques in stable and unstable angina. Routine staining of formalin-fixed, paraffin-embedded material was completed by the detection of T lymphocytes, macrophages, mast cells, smooth myocytes and grown-in capillaries using monoclonal antibodies (DAKO), as well as by the immunofluorescent demonstration of fibrinogen in the plaques. The plaques derived from patients with unstable angina showed a higher incidence of mast cells (significant) and macrophages (insignificant). These cells render the plaque more susceptible to rupture or fissuring. There was also significantly more frequent and quantitatively more abundant permeation of the plaque by fibrinogen that raises the chance of thrombosis. These findings support the view that unstable angina correlates with the phenomena that favour the rupture of the plaque and thrombosis. Electron microscopy has not been used so far to study coronary atherosclerotic plaques. This material includes 15 plaques from stable and 18 plaques from unstable angina. A cover of fibrin and blood platelets is a regular formation on the surface and in the superficial layer of the plaque from unstable angina. It contributes to the "thrombotic proneness" of the coronary artery. These plaques also show abundant elastic fibres. This pattern corresponds to myo-elastic intimal hyperplasia ("intimal thickening") where the production of intimal elastin constitutes an essential phenomenon. Intimal thickening is interpreted as a preatherosclerotic event. The presence of elastin reflects an early stage of the development of the plaque. The plaque from stable angina shows abundant collagen fibres, which aggravate the lesion.

Histological examination of the topography of the atrioventricular nodal artery within the triangle of Koch

The treatment of choice in patients with drug-resistant atrioventricular nodal reentry tachycardia is radiofrequency fast or slow pathway ablation. Ablation of the reentrant circuit in the region of the His bundle, when approached from the anterior-superior region (fast pathway); can result in complete AV block. This is less likely if the posterior-inferior (in the region of coronary sinus ostium) approach is used (slow pathway ablation). The possibility that radiofrequency energy may damage the vascular supply to the AV node must be considered. In order to confirm this hypothesis observation was conducted on the autopsy material of 50 human hearts (20 F, 30 M) from 18 to 81 years of age. Specimens were taken containing the triangle of Koch (the apex- right fibrous trigone, the base- coronary sinus ostium). These histological blocks were sectioned in the frontal plane and stained using Masson's method. Koch's triangle was divided in the sagittal plane into 3 parts: inferior (between the base and the attachment of the tricuspid valve), central (between the base and the apex of the right fibrous trigone) and superior (between this trigone and the tendon of Todaro). It was observed that the AVN artery at the coronary sinus ostium level (the base of the triangle of Koch) was positioned in 68% in the central and in 32% in the inferior part of Koch's triangle. The AVN artery in the central part was removed from the endocardium 1 mm (18%), 2 mm (42%), 3 mm (22%), 4 mm (18%). In the inferior part 1 mm (26%), 2 mm (37%), 3 mm (37%). No statistically significant relationship was observed between those groups.

CONCLUSIONS

1) in 20% of examined hearts the AVN artery lay just beneath the endocardium near the coronary sinus ostium 2) there is a risk of the AVN artery coagulation during radiofrequency ablation in the slow pathway region.

Acute infarction of the left ventricular papillary muscle: electrocardiographic pattern and recognition of its location

BACKGROUND AND HYPOTHESIS

ST-segment depression during acute myocardial infarction (AMI) is known to herald serious hemodynamic complications. Since the mechanism of this dependence is not clear, we reinvestigated the old concept of papillary muscle infarction (PMI) as a cause of marked ST depression.

METHODS

Autopsies and morpho-electrocardiographic cor-relations were performed in 53 patients with AMI involving one or both left ventricular papillary muscles, and in 10 patients with AMI, but without acute PMI.

RESULTS

ST-segment depression > or = 1 mm in at least two leads (mean 3.6 +/- 2.2 mm) was found in 46 (86.8%) patients with, and in one without acute PMI. Thus, the sensitivity and specificity in selecting patients with acute PMI from among those with AMI were 86.8 and 90%, respectively, with an overall accuracy of diagnosis of acute PMI in the course of AMI of 87.3%. Among 26 patients with ST elevation consistent with diagnosis of AMI, ST depression, recorded in 22 patients, was insignificantly greater than in 24 of 27 patients without ST elevation: 4.1 +/- 2.9 versus 3.1 +/- 1.2 mm. Localization of ST depression in the limb leads allowed recognition of which papillary muscle suffered from acute infarction: ST depression in the inferior leads was seen only in patients with anterolateral PMI, whereas in leads I and/or a VL it was seen only in cases with posteromedial PMI. This rule was also valid in patients without concomitant ST elevation.

CONCLUSION

Patients with acute PMI show marked ST-segment depression. Its location in the limb leads allows recognition of which papillary muscle has undergone necrosis. This cause of marked ST depression in patients with AMI may explain the high mortality in this particular group.

Dilated cardiomyopathy in children: clinical course and prognosis

The clinical profile of 19 patients with dilated cardiomyopathy ages 2-18 years (mean 13.4 +/- 4 years) was reviewed to detect any factors that might be predictive for their survival. Follow-up range from 5 to 105 months (mean 39 +/- 33 months). Routine treatment consisted of digitalis and diuretics: 14 patients received antiarrhythmics, 6 received vasodilators, and 12 were managed with immunosuppression. There were 12 survivors and 7 nonsurvivors: The 1-year mortality was 21.2% and the 2-year mortality 35.8%. All deaths were within first 2 years. Of the 12 patients who survived 2 years, a significant improvement was noticed in 9. In 3 patients tachycardia-induced cardiomyopathy was diagnosed, and abolition of supraventricular tachycardia was followed by improvement and regression of cardiomegaly. Endomyocardial biopsy was performed in 16 patients. Four with a histologic diagnosis of active myocarditis survived, and in 3 of them a considerable improvement was noticed. Of the 12 patients with nonspecific histologic findings, 6 died (p < 0.05). There were no significant differences between survivors and nonsurvivors for any of the following parameters: incidence of severe heart failure (NYHA class III-IV) and severe ventricular arrhythmias (Lown class III-V), relative heart volume, echocardiographic left ventricular diastolic diameter and shortening fraction, and the hemodynamic parameters of cardiac index, left ventricular ejection fraction, left ventricular end-diastolic pressure, and left ventricular end-diastolic volume index.

[Familial dilated cardiomyopathy with autosomal mode of inheritance. Case report]

Familial occurrence of dilated cardiomyopathy is estimated by 2-20%. We present a family with dilated cardiomyopathy inherited in an autosomal dominant way. We examined 9 members of the family, most of them are asymptomatic.

Acromelic frontonasal "dysplasia": further delineation of a subtype with brain malformation and polydactyly (Toriello syndrome)

We report on a stillborn boy with frontonasal malformation (Sedano-Jiràsek type D-DeMyer type I), associated with encephalocoele, occipital meningocele and preaxial polydactyly of the feet. This form of frontonasal dysplasia was documented previously in a few other cases with various combinations of postaxial polydactyly, tibial hypoplasia, epibulbar dermoid, occipital encephalocoele, corpus callosum agenesis and Dandy-Walker malformation. Most cases are sporadic.

[Mixed tumor of the lacrimal gland]

Presented is a case of a woman-patient with a mixed tumor of the lacrimal gland which grew to an infrequently seen size. The tumor was excised and identified as a non-malignant one. Three years after surgery came a renewed extensive expansion of the tumor. Exenteration of the orbit was performed and histopathological examination revealed a mixed malignant tumor of the gland.