Septal Ablation Versus Surgical Myomectomy for Hypertrophic Obstructive Cardiomyopathy

PURPOSE OF REVIEW

Patients with hypertrophic cardiomyopathy (HCM) who have left ventricular outflow tract obstruction (LVOTO) often experience severe symptoms and functional limitation. Relief of LVOTO can be achieved by two invasive interventions, i.e., surgery myectomy and alcohol septal ablation (ASA), leading in experienced hands to a dramatic improvement in clinical status. Despite extensive research, however, the choice of the best option in individual patients remains challenging and poses numerous clinical dilemmas.

RECENT FINDINGS

Invasive strategies have been recently incorporated in recommendations for the diagnosis and treatment of HCM on both sides of the Atlantic. These guidelines are based on a bulk of well-designed but retrospective studies as well as on expert opinions. Evidence now exists that adequate evaluation and management of HCM requires a multidisciplinary team capable of choosing the best available options. Management of LVOTO still varies largely based on local expertise and patient preference. Following the trend that has emerged for other cardiac diseases amenable to invasive interventions, the concept of a "HCM heart team" is coming of age.

Ticagrelor versus Clopidogrel in high bleeding risk patients presenting with Acute Coronary Syndromes: insights from the multicenter START-ANTIPLATELET registry

Background

Optimal dual antiplatelet therapy in high bleeding risk (HBR) patients with acute coronary syndromes (ACS) remains debated. Although current guidelines recommend the use of potent P2Y12 inhibitors in these patients (according to the labeled indications), clopidogrel is frequently used in clinical practice based on a perceived advantage in terms of safety in the HBR population.

Purpose

We sought to investigate the use of clopidogrel versus ticagrelor in consecutive HBR ACS patients and their impact on ischemic and bleeding events at 1 year.

Methods

ACS patients enrolled in the START-ANTIPLATELET registry with at least 1 HBR criterion were included in the present analysis and stratified according to DAPT type (clopidogrel versus ticagrelor). The primary endpoint was net adverse clinical endpoint (NACE), defined as a composite of all-cause death, myocardial infarction, stroke, and major bleeding. The secondary endpoints were major adverse cardiac and cerebral events (MACE), defined as a composite of all-cause death, myocardial infarction and stroke, each individual component of NACE and MACE, and target vessel revascularization.

Results

Among a total of 1,209 patients with 1-year follow-up in the registry, 383 patients were considered at HBR, of whom 174 (45.4%) were on clopidogrel and 209 (54.6%) on ticagrelor. Clopidogrel was more likely to be administered in patients at increased ischemic and bleeding risk, while ticagrelor in those undergoing percutaneous coronary intervention. Mean DAPT duration was longer in the ticagrelor group than in the clopidogrel group (10.40±4.29 versus 9.35±5.4; p-value=0.03). At 1-year follow-up, the risk of NACE and MACE events was significantly higher in the clopidogrel than in the ticagrelor group (NACE: HR 1.82; 95% CI 1.07–3.09; p-value=0.02; MACE: HR 1.83; 95% CI 1.04–3.24; p-value=0.03) (Figure). After multivariate adjustment for clinical and procedural characteristics, no difference in NACEs nor MACEs was observed between patients on clopidogrel versus ticagrelor (NACE: adjusted HR 1.27; 95% CI 0.71–2.27; p-value=0.42; MACE: adjusted HR 1.19; 95% CI 0.63–2.24; p-value=0.59) (Figure). Age, number of HBR criteria, and mean DAPT duration were independent predictors of NACEs.

Conclusions

In a real-world ACS registry, approximately 50% of patients are at HBR and frequently treated with clopidogrel. In HBR ACS patients, no difference was observed in ischemic and bleeding events between clopidogrel and ticagrelor after adjustment for potential confounders.

Kaplan-Meier curves at 1-year follow-up.

Funding Acknowledgement

Type of funding source: None

Common variants of human TERT and TERC genes and susceptibility to sporadic Alzheimers disease

Studies investigating telomere length in association with cognitive decline, dementia, and sporadic Alzheimer's disease (AD) have frequently found shorter telomeres to be associated with the development of AD and telomerase expression with pathological processes in AD. Human telomerase is constituted by two components: the telomerase reverse transcriptase (TERT) and the telomerase RNA component (TERC). Genetic variation at the two loci has been investigated in relation to telomere length, longevity, and common diseases of advanced age, but not in relation to AD. We examined three polymorphisms of the TERT gene (VNTR MNS16A, rs2853691, rs33954691) and three polymorphisms of the TERC gene (rs12696304, rs3772190, rs16847897) in a sample of 220 AD patients and 146 controls. MNS16A LL genotype was found to be associated with an increased risk of AD only in males [interaction term adjusted OR=3.55 (95% CI 1.2-10.2)]. The three TERC single nucleotide polymorphisms are in strict linkage disequilibrium and their genotype combinations influenced the age at AD onset (AAO). The combined genotype GG-TT-CC was associated with a mean AAO six years lower (70.5±6.7) than that associated with the other genotype combinations (76.04±6.7, p=0.01). The fact that the MNS16 L allele has been reported to lower TERT expression, and that the TERC alleles G, T, C (rs12696304, rs3772190, rs16847897 in this order have been repeatedly found associated with shorter LTL, seems to corroborate the hypothesis of a role of telomere length and telomerase in AD susceptibility.

Patent foramen ovale and cryptogenic stroke: from studies to clinical practice: Position paper of the Italian Chapter, International Society Cardiovascular Ultrasound

BACKGROUND

Over the last two decades the interest on patent foramen ovale (PFO) as a cause of cardioembolism in cryptogenic stroke has tremendously increased, thanks to the availability of better techniques to diagnose cardiac right-to-left shunt by ultrasounds and of percutaneous means of PFO treatment with interventional techniques. Many studies have been published that have attempted to define diagnostic methodology, prognosis, and optimal treatment (pharmacological or percutaneous closure) of PFO patients with cryptogenic stroke. Unfortunately, even today, definitive evidence is still lacking, and clinical management is not consistent among cardiologists.

AIMS

This review aims to evaluate the role of PFO in cryptogenic stroke, the diagnostic accuracy of transcranial Doppler, contrast transthoracic and transesophageal echocardiography in the diagnosis of left-fright shunt and PFO; and discuss the indications to medical treatment and percutaneous closure of PFO.

METHODS

All studies published in the literature on PFO and cryptogenic stroke are considered and discussed.

RESULTS

We define an appropriate diagnostic and clinical management of PFO patients with cryptogenic stroke.

CONCLUSION

After many years of interest on PFO and many concluded studies, there are still no definitive data. However, we are on good track for an appropriate management of PFO patients and cryptogenic stroke.

Diagnostic accuracy of 320-row computed tomography as compared with invasive coronary angiography in unselected, consecutive patients with suspected coronary artery disease

Noninvasive coronary angiography with multislice computed tomography (CT) scanners is feasible with high sensitivity and negative predictive value. The radiation exposure associated with this technique, however, is high and concerns in the widespread use of CT have arisen. We evaluated the diagnostic accuracy of coronary angiography using 320-row CT, which avoids exposure-intensive overscanning and overranging. We prospectively studied 118 unselected consecutive patients with suspected coronary artery disease (CAD) referred for invasive coronary angiography (ICA). All patients had 320-row CT within 1 week of ICA, which, together with quantitative analysis, served as the reference standard. Of the 65 out of 118 patients who were diagnosed as having CAD by ICA, 64 (98 %) were correctly identified at 320-row CT. Noteworthy, 320-row CT correctly detected CAD in 3 patients with atrial fibrillation and ruled out the disease in the other 8 patients. From 151 significant coronary stenoses detected on ICA, 137 (91 %) were correctly identified with 320-row CT. In the per-patient analysis, sensitivity and specificity of 320-row CT were 98 and 91 %, respectively. In the per-vessel analysis, sensitivity and specificity of 320-row CT were 93 and 95 %, respectively. In the per segment analysis, sensitivity and specificity of 320-row CT were 91 and 99 %, respectively. Diameter stenosis determined with the use of CT showed good correlation with ICA (P < 0.001, R = 0.81) without significant underestimation or overestimation (-3.1 ± 24.4 %; P = 0.08). Comparison of CT with ICA revealed a significantly smaller effective radiation dose (3.1 ± 2.3 vs. 6.5 ± 4.2 mSv; P < 0.05) and amount of contrast agent required (99 ± 51 vs. 65 ± 42 ml, P < 0.05) for 320 row CT. The present study in an unselected population including patients with atrial fibrillation demonstrates that 320-row CT may significantly reduce the radiation dose and amount of contrast agent required compared with ICA while maintaining a very high diagnostic accuracy.

Replication timing of two human common fragile sites: FRA1H and FRA2G

The mammalian chromosomes present specific sites of gaps or breaks, the common fragile sites (CFSs), when the cells are exposed to DNA replication stress or to some DNA binding compounds. CFSs span hundreds or thousands of kilobases. The analysis of these sequences has not definitively clarified the causes of their fragility. There is considerable evidence that CFSs are regions of late or slowed replication in the presence of sequence elements that have the propensity to form secondary structures, and that the cytogenetic expression of CFSs may be due to unreplicated DNA. In order to analyse the relationship between DNA replication time and fragility, in this work we have investigated the timing of replication of sequences mapping within two CFSs (FRA1H and FRA2G), of syntenic non-fragile sequences and of early and late replicating control sequences by using fluorescent in situ hybridization on interphase nuclei, conventional fluorescence microscopy and confocal microscopy. Our results indicate that the fragile sequences are slow replicating and that they enter G2 phase unreplicated with very high frequency. Thus these regions could sometimes reach mitosis unreplicated or undercondensed and be expressed as chromosome gaps/breakages.

Characterization of the human common fragile site FRA2G

Common fragile sites are nonrandom loci that show gaps and breaks when cells are exposed to specific compounds. They are preferentially involved in recombination, chromosomal rearrangements, and foreign DNA integration. These sites have been suggested to play a role in chromosome instability observed in cancer. In this work we used a FISH-based approach to identify a BAC contig that spans the FRA2G fragile site located at the 2q31 region. Our observations indicate that a very fragile region spanning at least 450 kb is present within a large fragile region that extends over 1 Mb. At least seven genes are mapped in the fragile region. One of these seems to be a good candidate as a potential tumor suppressor gene impaired by the recurrent deletions observed at the 2q31 region in some neoplasms. In the fragile region, a considerable number of regions of high flexibility that may be related to the fragility are present.

Effect of sildenafil citrate upon myocardial ischemia in patients with chronic stable angina in therapy with beta-blockers

BACKGROUND

It has been suggested that phosphodiesterase 5 (PDE5) inhibition is potentially hazardous and that it increases the risk of cardiac events in patients with coronary artery disease. This study sought to evaluate whether PDE5 inhibition with sildenafil exerts any effect on exercise-induced myocardial ischemia in patients on beta-blockers.

METHODS

Fourteen patients underwent a baseline exercise test off-therapy and were then started on atenolol (100 mg once daily). After a run-in phase of 1 week, patients underwent a second exercise test and were randomized to receive either sildenafil (50 mg) or placebo given in a random order on two different occasions, 2 days apart. Exercise test was repeated 2 hours after the administration of sildenafil or placebo.

RESULTS

All patients had a > 1 mm ST-segment depression while off-therapy. Eight patients had a negative exercise test response after atenolol, which was unaltered by the adjunct of either sildenafil or placebo. In the remaining subjects, atenolol significantly prolonged the time to 1 mm ST-segment depression and the exercise time. Sildenafil and placebo did not reverse the beneficial effect of atenolol upon exercise-induced myocardial ischemia.

CONCLUSIONS

PDE5 inhibition does not worsen exercise capacity and exercise-induced myocardial ischemia in patients with chronic stable angina whose symptoms and exercise test response are well controlled by beta-blocker therapy.

5S ribosomal and U1 small nuclear RNA genes: a new linkage type in the genome of a crustacean that has three different tandemly repeated units containing 5S ribosomal DNA sequences

We investigated the 5S ribosomal RNA (rRNA) genes of the isopod crustacean Asellus aquaticus. Using PCR amplification, three different tandemly repeated units containing 5S rDNA were identified. Two of the three sequences were cloned and sequenced. One of them was 1842 bp and presented a 5S rRNA gene and a U1 small nuclear RNA (snRNA) gene. This type of linkage had never been observed before. The other repeat consisted of 477 bp and contained only an incomplete 5S rRNA gene lacking the first eight nucleotides and a spacer sequence. The third sequence was 6553 bp long and contained a 5S rRNA gene and the four core histone genes. The PCR products were used as probes in fluorescent in situ hybridization (FISH) experiments to locate them on chromosomes of A. aquaticus. The possible evolutionary origin of the three repeated units is discussed.

Clustering of two fragile sites and seven homeobox genes in human chromosome region 2q31-->q32.1

In this study we have used FISH to examine the relationship between a group of homeobox genes, namely DLX1/DLX2, EVX2 and four HOXD genes (10, 11, 12, 13), that map to region q31 on chromosome 2, and the FRA2G and FRA2H fragile sites located at 2q31 and 2q32.1 respectively. Our results indicate that these homeobox genes lie between the two fragile regions.

Sex chromosome differentiation revealed by genomic in-situ hybridization

In this work, genomic in-situ hybridization (GISH) was used to study the sex chromosome molecular differentiation on chromosomes of male and female individuals of the isopod crustacean Asellus aquaticus. As a composite hybridization probe, we contemporaneously used male and female whole genomic DNA differently labelled in the presence of an excess of unlabelled DNA of the female homogametic sex. The karyotype of A. aquaticius normally displays eight homomorphic chromosome pairs, but a heteromorphic sex chromosome pair is present in about a quarter of the males of a natural population previously identified by us. GISH did not reveal any sex chromosome molecular differentiation on the male and female homomorphic sex chromosome pair, and the karyotypes of these individuals were equally labelled by the male- and female-derived probe, while the heteromorphic Y chromosome showed a differentially labelled region only with the male-derived probe. This region evidently contains male-specific sequences but, because no similar hybridized region is observed on the male homomorphic chromosome pair, they are probably not important for sex determination but represent a molecular differentiation acquired from the Y chromosome.

Organization, nucleotide sequence, and chromosomal mapping of a tandemly repeated unit containing the four core histone genes and a 5S rRNA gene in an isopod crustacean species

A tandemly repeated unit of 6553 bp containing a copy of the four core histone genes H2B, H2A, H3, and H4, and also a 5S rRNA gene, was amplified by PCR from genomic DNA of the isopod crustacean Asellus aquaticus. The linkage between 5S rRNA genes and histone genes has been so far observed in only one other organism, the anostrac crustacean Artemia salina. The gene cluster was cloned and sequenced. The histone genes, in their 3' flanking region, have the interesting feature of possessing two different mRNA termination signals, the stem-loop structure and the AATAAA sequence. A part of the PCR product was used as a probe in FISH experiments to locate the gene cluster on an inter-individually variable number of chromosomes from 6 to 12 per diploid cell, always in a terminal position and never associated with the heterochromatic areas. Fluorescence in situ hybridization (FISH) was also performed on preparations of released chromatin and the reiteration level of the gene cluster was determined as approximately 200-300 copies per haploid genome.

Acute anti-ischemic effect of testosterone in men with coronary artery disease

BACKGROUND

The role of testosterone on the development of coronary artery disease in men is controversial. The evidence that men have a greater incidence of coronary artery disease than women of a similar age suggests a possible causal role of testosterone. Conversely, recent studies have shown that the hormone improves endothelium-dependent relaxation of coronary arteries in men. Accordingly, the aim of the present study was to evaluate the effect of acute administration of testosterone on exercise-induced myocardial ischemia in men.

METHODS AND RESULTS

After withdrawal of antianginal therapy, 14 men (mean age, 58+/-4 years) with coronary artery disease underwent 3 exercise tests according to the modified Bruce protocol on 3 different days (baseline and either testosterone or placebo given in a random order). The exercise tests were performed 30 minutes after administration of testosterone (2.5 mg IV in 5 minutes) or placebo. All patients showed at least 1-mm ST-segment depression during the baseline exercise test and after placebo, whereas only 10 patients had a positive exercise test after testosterone. Chest pain during exercise was reported by 12 patients during baseline and placebo exercise tests and by 8 patients after testosterone. Compared with placebo, testosterone increased time to 1-mm ST-segment depression (579+/-204 versus 471+/-210 seconds; P<0. 01) and total exercise time (631+/-180 versus 541+/-204 seconds; P<0. 01). Testosterone significantly increased heart rate at the onset of 1-mm ST-segment depression (135+/-12 versus 123+/-14 bpm; P<0.01) and at peak exercise (140+/-12 versus 132+/-12 bpm; P<0.01) and the rate-pressure product at the onset of 1-mm ST-segment depression (24 213+/-3750 versus 21 619+/-3542 mm Hgxbpm; P<0.05) and at peak exercise (26 746+/-3109 versus 22 527+/-5443 mm Hgxbpm; P<0.05).

CONCLUSIONS

Short-term administration of testosterone induces a beneficial effect on exercise-induced myocardial ischemia in men with coronary artery disease. This effect may be related to a direct coronary-relaxing effect.

Nucleotide sequence and chromosomal mapping of the 5S rDNA repeat of the crustacean Proasellus coxalis

In this investigation we analysed the 5S rRNA genes of the isopod crustacean Proasellus coxalis, 5S rDNA hybridization of digested genomic DNA and amplification by PCR demonstrate that these genes are organized in tandem repeats of 589 bp, 120 of which represent the coding sequence and 469 the spacer sequence. Proasellus coxalis is the first crustacean species in which 5S rRNA genes have been found tandemly arranged without being linked to other repeated genes. The PCR product has been used as a probe in FISH to locate the 5S rRNA genes on two chromosome pairs of the P. coxalis karyotype. Comparison of the 5S rRNA sequence of this species with previously published sequences of six other crustacean species shows the existence of a good correlation between phylogenetic relationships and sequence identity.

Longitudinal differentiation of chromosomes of Asellus aquaticus (Crust. Isop.) by in situ nick translation using restriction enzymes and DNase I

Asellus aquaticus is an isopod crustacean whose chromosomes cannot be differentiated by G- or R-banding techniques. In this work, we have obtained a longitudinal differentiation of these chromosomes by in situ nick translation using restriction enzymes (HaeIII, DraI and BamHI) and DNase I digestions. The four nucleases, with different efficiencies, have produced similar labelling patterns. Staining with DAPI, Giemsa and chromomycin A3 reveals that the DNA of the nick-translated regions is generally more resistant to extraction from the chromosome. The results obtained on the heteromorphic sex chromosome pair observed in about a quarter of the males of a natural population allow several hypotheses to be advanced on the nature and origin of chromosome dimorphism.

Effects of angiotensin-converting enzyme inhibition on left ventricular geometric patterns in patients with essential hypertension

Although angiotensin-converting enzyme inhibitors have been shown to affect left ventricular (LV) remodeling favorably in several conditions, it remains unclear whether they can influence LV geometric pattern in hypertension. To address this issue, 122 patients (71 men and 51 women; mean age = 51 +/- 10 years) with mild to moderate hypertension were studied prospectively. All underwent clinical evaluation and Doppler echocardiography at entry and more than 2 years of quinapril therapy (10-40 mg/day). According to either LV mass (normal if < 131 g/m2 for men or < 100 g/m2 for women) or the ratio of LV posterior wall thickness to diastolic diameter (RWT; normal if < 0.45) at baseline, 58 patients had normal mass and RWT, 18 patients had concentric remodelling (i.e., normal mass but increased RWT), 24 patients had eccentric hypertrophy (i.e., increased mass but normal RWT), and 22 patients had concentric hypertrophy (i.e., increase in both mass and RWT). After 6 months of quinapril therapy, all patients with normal left ventricles showed the maintenance of mass and RWT within normal limits. Patients with concentric remodeling showed no increase in mass but had a significant decrease in RWT. Patients with eccentric hypertrophy exhibited a significant reduction in mass with no substantial change in RWT. Patients with concentric hypertrophy had a significant reduction in both mass and RWT. Changes in LV mass and geometry were maintained during the 2-year period of treatment and were paralleled by improvements in Doppler indices of LV diastolic function in each group. It is concluded that quinapril, with its well-known effects on LV hypertrophy, modifies the LV geometric pattern of hypertensive patients favorably, regardless of the presence of an abnormal LV mass or RWT.

Heterochromatin and ribosomal genes in Asellus aquaticus (Crust. Isop.)

In the present investigation chromosomal preparations of Asellus aquaticus were sequentially stained with chromomycin A3 to reveal the heterochromatic areas, hybridized in situ with rDNA probes in order to map the ribosomal genes and finally silver stained to check the transcriptional activity of these genes. The results indicate the existence of a substantial correspondence of location and size among the heterochromatic regions and the regions over which the in situ hybridization signals spread. The ribosomal genes, quite independently of their location in the secondary constriction, can be silver stained and thus appear to be transcriptionally active. The ribosomal sequences also hybridize to the entire heterochromatic areas observed on the probable Y chromosome identified in some males of a natural population. These rRNA genes are only rarely transcriptionally active.

Study of the relationships between common fragile sites, chromosome breakages and sister chromatid exchanges

This paper reports the results of an investigation into the relationship between common fragile sites and sister chromatid exchanges (SCE). Human leukocyte cultures were grown in two different media, one complete (RPMI 1640) and one deficient in folic acid and thymidine (199M). Some of the cultures were treated with DAPI, a non-intercalating compound which binds preferentially to the AT bases of DNA and is capable of inducing fragile sites. Bromodeoxyuridine (BrdU) was added to all the cultures for SCE analysis. Chromomycin A3 was used for mapping lesions and SCEs by R-banding. A total of 400 cells was examined. The main results show that: BrdU, probably by re-equilibrating the unbalanced nucleotide pool of the 199 culture medium, interferes with the synergism between this culture medium and DAPI in inducing the expression of fragile sites; the SCE frequency per cell is not increased by DAPI in both culture media, therefore this compound does not seem to cause any damage to the DNA and seems merely to act by inhibiting the normal condensation of a subset of fragile sites that possess DAPI-specific base sequences; even in the absence of chromosomal lesions, the fragile sites are significantly preferred as SCE sites to non-fragile sites, whereas in the presence of a lesion, both fragile and non-fragile sites have the same likelihood of undergoing SCE. All this indicates that the presence of a lesion strongly favours SCE formation and that common fragile sites are probably chromosome regions preferentially damaged during the S phase.

Functional significance of myocellular hypertrophy in dilated cardiomyopathy: histomorphometric analysis on 40 endomyocardial biopsies

Dilated cardiomyopathy is characterized by an increase in myocardial mass. In order to study the functional significance of myocellular hypertrophy in dilated cardiomyopathy, 40 left ventricular endomyocardial biopsies were investigated, by comparing morphometrical data with functional indexes. The extent of myofibril volume fraction was directly associated with a better functional condition, as measured by ejection fraction (p < 0.01) and cardiac index (p < 0.05). Patients with oversize nuclei (nuclear area being > or = 70 microns 2) had a worse functional status (p < 0.05), as determined by ejection fraction and cardiac index. Finally, the extent of interstitial fibrosis was directly correlated to mean right atrial pressure (p < 0.01), right ventricular end-diastolic pressure (p < 0.02) and mean pulmonary artery pressure (p < 0.02). In conclusion, a worse functional status correlates with a reduced myofibril volume fraction and an oversize nuclear area, as in hypertrophic cells undergoing regressive changes.

Histomorphometric features predict 1-year outcome of patients with idiopathic dilated cardiomyopathy considered to be at low priority for cardiac transplantation

Cardiac transplantation for patients with idiopathic dilated cardiomyopathy (IDC) and poor left ventricular function usually is postponed until symptoms have become intolerable. However, the short-term prognosis of this subset of patients has been defined poorly. Accordingly, the 1-year outcome was investigated in 30 patients with IDC with an ejection fraction < or = 25% who showed a stabilized clinical condition at assessment for transplantation and were therefore considered at low priority for surgery. During follow-up, 10 patients (group A) showed a poor outcome: 2 died suddenly, and 8 had hemodynamic failure (4 of whom underwent transplantation and 4 of whom died from heart failure while on the waiting list). The remaining 20 patients (group B) had a benign outcome. At assessment for cardiac transplantation, clinical and electrocardiographic features, left ventricular dimension, and ejection fraction were similar between the two groups. However, group A patients had higher left ventricular end-diastolic pressure (p < 0.03) and lower cardiac index (p < 0.02) and stroke volume index (p < 0.03) with respect to group B patients. In addition, the former had a lower myofibril volume fraction (p < 0.001) and a higher nuclear area (p < 0.001) compared with the latter. Multivariate analysis selected myofibril volume fraction (p < 0.001) and nuclear area (p < 0.005) as the only independent predictors of a poor 1-year outcome. The combination of myofibril volume fraction < or = 89% and nuclear area > 50 microns 2 was found in all group A patients (sensitivity 100%) but in only 2 group B patients (specificity 90%). It is concluded that in patients with IDC considered at low priority for cardiac transplantation: (1) the 1-year freedom from a cardiac event is lower than that currently expected with surgery; (2) histomorphometric features, that is, the concurrency of low myofibril volume fraction and increased nuclear area, predict short-term outcome; and (3) endomyocardial biopsy at assessment for cardiac transplantation might improve the rationalization of the timing of the procedure.

Changes in pulmonary hemodynamics predict benefits in exercise capacity after ACE inhibition in patients with mild to moderate congestive heart failure

Several causes may affect the efficacy of angiotensin-converting enzyme (ACE) inhibitors in congestive heart failure (CHF). The present study was undertaken to identify what factors might predict benefits in exercise capacity after ACE inhibition in 22 patients with mild to moderate CHF. All patients underwent hemodynamic evaluation before and following an oral dose of quinapril (20 mg). They were then treated daily with 20 mg of quinapril and underwent exercise stress test off-drugs 1 day and 6 months later. Patients were grouped according to their relative changes in vascular resistances after quinapril: Group A (n = 15) showed a greater decrease in pulmonary vascular resistance (PVR) than in systemic vascular resistance (SVR) (% delta PVR/% delta SVR > 1). The opposite occurred in Group B (n = 7). Comparison of pretreatment baseline features revealed that the two groups had similar biochemical and hormonal variables, cardiac index, and SVR. Conversely, Group A patients had higher (p < 0.05) pulmonary artery pressure and PVR compared with Group B patients. Following quinapril, Group A patients showed a greater (p < 0.05) increase in cardiac index than Group B patients, despite a similar reduction in SVR. Accordingly, 1-day drug treatment significantly (p < 0.001) increased exercise duration in Group A (+29%), but not in Group B patients (+7%). Benefits in exercise capacity were still significant (p < 0.001) 6 months later.(ABSTRACT TRUNCATED AT 250 WORDS)

Chromosome length and DNA loop size during early embryonic development of Xenopus laevis

The looped organization of the eukaryotic genome mediated by a skeletal framework of non-histone proteins is conserved throughout the cell cycle. The radial loop/scaffold model envisages that the higher order architecture of metaphase chromosomes relies on an axial structure around which looped DNA domains are radially arranged through stable attachment sites. In this light we investigated the relationship between the looped organization and overall morphology of chromosomes. In developing Xenopus laevis embryos at gastrulation, the bulk of the loops associated with histone-depleted nuclei exhibit a significant size increase, as visualized by fluorescence microscopy of the fully extended DNA halo surrounding high salt treated, ethidium bromide stained nuclei. This implies a reduction in the number of looped domains anchored to the supporting nucleoskeletal structure. The cytological analysis of metaphase plates from acetic acid fixed whole embryos, carried out in the absence of drugs inducing chromosome condensation, reveals a progressive thickening and shortening of metaphase chromosomes during development. We interpret these findings as a strong indication that the size and number of DNA loops influence the thickness and length of the chromosomes, respectively. The quantitative analysis of chromosome length distributions at different developmental stages suggests that the shortening is timed differently in different embryonic cells.

[The relationship between anomalies in the autonomous nervous system and left ventricular dysfunction in patients with hypertrophic cardiomyopathy]

This study was undertaken to assess autonomic nervous system (ANS) activity and its relation to left ventricular function in 40 patients (mean age: 41 +/- 17 years) with hypertrophic cardiomyopathy (HC), in sinus rhythm, off-drugs. Patients were grouped according to the results of radionuclide angiography: 26 had an ejection fraction > 50% (Group A), whereas 14 had an ejection fraction < or = 50% (Group B). Evaluation of parasympathetic activity showed abnormalities in: heart rate (HR) response during Valsalva (< or = 1.1) in 2 Group A (8%) and 12 Group B (86%) patients (p < 0.001); HR variability during deep breathing (< or = 10 b/min) in 2 Group A (8%) and 14 Group B (100%) patients (p < 0.001); immediate HR response to standing (30:15 < or = 1.0) in 2 Group A (8%) and 6 Group B (43%) patients (p < 0.025). Assessment of sympathetic activity showed abnormalities in: systolic blood pressure fall to standing (> 20 mmHg) in 2 Group B (14%) patients only (NS); diastolic blood pressure response to handgrip (< 10 mmHg) in 4 Group B (29%) patients only (p < 0.025). Thus, in HC: impaired parasympathetic control is common in those patients showing left ventricular dysfunction; concurrent sympathetic abnormality may also occur in this subgroup of patients; ANS dysfunction seems to be merely an epiphenomenon which marks the severity of left ventricular derangement.

Resting and ambulatory ECG predictors of mode of death in dilated cardiomyopathy

With the purpose of verifying whether the electrocardiogram (ECG) pattern alone can predict the mode of death in dilated cardiomyopathy, data from 12-lead ECGs and 48-hour arrhythmia monitoring were evaluated in 67 patients with dilated cardiomyopathy. During a mean follow-up period of 3 +/- 2 years, death from congestive heart failure occurred in 18 patients (27%), whereas 10 (15%) died suddenly (NS). Multivariate analysis showed that left bundle branch block (p < 0.001) and left atrial enlargement (p < 0.001) were independently related to death from congestive heart failure. Ventricular arrhythmias of Lown grade 4A or 4B (p < 0.001) and repolarization time, as assessed by QTc-QRS interval (p < 0.05), were independent predictors of sudden death. It is concluded that ECG features alone may be helpful for risk factor characterization of dilated cardiomyopathy patients, provided that multiple ECG criteria are utilized at time of diagnosis.

Pathologic evidence of extensive left ventricular involvement in arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (also known as arrhythmogenic right ventricular dysplasia) is characterized by adipose or fibroadipose tissue replacement of the right ventricular myocardium, whereas the left ventricle is substantively spared. Two cases of the disease with evidence of extensive left ventricular involvement at pathologic examination are described. Hearts from two patients who died suddenly showed full-thickness right ventricular fatty infiltration associated with extensive left ventricular involvement (greater than 50% of myocardial thickness). These findings might explain the reported clinical features of left ventricle dysfunction in a subset of patients with arrhythmogenic right ventricular cardiomyopathy. In view of the biventricular involvement of the disease, it should simply be termed "arrhythmogenic cardiomyopathy."

The effect of caffeine on DAPI-inducible fragile sites

DAPI is a non-intercalating compound which binds specifically to the AT bases of DNA. When leukocytes are grown in complete medium (RPMI 1640) DAPI induces the expression of three fragile sites on human chromosomes and if the medium is deficient in folic acid and thymidine (199M) it induces 19 fragile sites. Caffeine has been found by different authors to considerably enhance the expression of chromosome breaks which have been produced by other agents. When it is added to the complete medium after DAPI, it elicits almost all the sites that DAPI only induces in incomplete medium. When caffeine is added after DAPI to incomplete medium, it does not significantly or unidirectionally modify the capacity of the two subjects examined to elicit fragile sites. The analysis of these results, when correlated with that of the mitotic index, reveals a different sensitivity of the two subjects to the combined DAPI-caffeine treatment. The results are quite compatible with the hypothesis that the DAPI-induced fragile sites are DNA regions which are not accurately replicated during the S phase.

Magnetic resonance imaging for assessment of apical hypertrophy in hypertrophic cardiomyopathy

The purpose of the study was to evaluate the value of magnetic resonance imaging as compared with two-dimensional echocardiography for a reliable assessment of the degree and distribution of apical hypertrophy in hypertrophic cardiomyopathy (HCM). The study includes 10 HCM patients (8 males and 2 females, mean age: 42 +/- 7 years). Two-dimensional echocardiography was not definitive in assessing the abnormal thickening of the apical myocardium in two patients. Two other patients had inadequate echocardiographic visualization of the lower left ventricle due to technical reasons. At magnetic resonance imaging, 3 patients showed localized hypertrophy at the left ventricular apex only. Three other patients had evidence of hypertrophy at the apex as well as at the left ventricular free wall. In four patients, the hypertrophy was detected at either the apex or the lower interventricular septum. It is concluded that magnetic resonance imaging might provide an accurate assessment of myocardial hypertrophy in HCM patients. This technique appears to be of major value in those with wall thickening localized to (or predominant in) the apical portion of the ventricle.

Sudden death during pregnancy in hypertrophic cardiomyopathy

A 27-year-old asymptomatic woman became pregnant 6 months after a diagnosis of hypertrophic cardiomyopathy and was well until 28 weeks' gestation when she died suddenly while running up stairs. The potential pathophysiological mechanisms of sudden death during pregnancy in hypertrophic cardiomyopathy, as well as the diagnostic and therapeutic implications, are discussed.

Electrocardiographic correlates with left ventricular morphology in idiopathic dilated cardiomyopathy

The purpose of the present study was to verify whether the electrocardiographic pattern of patients with idiopathic dilated cardiomyopathy (IDC) might be useful in predicting measurements of left ventricular (LV) morphology. A total of 12 electrocardiographic criteria for LV enlargement were evaluated in 67 patients with IDC, aged 14 to 68 years (mean 48), and were correlated to LV wall thickness, volume and mass, as assessed at angiography (all patients) and echocardiography (50 patients). Linear regression analysis showed weak correlations between multiple electrocardiographic criteria and LV wall thickness, volume and mass. Multiple logistic regression analysis showed that total 12-lead QRS amplitude, voltage criteria of Sokolow and Lyon, overshoot and U-wave inversion were the variables significantly related to LV wall thickness, as assessed by angiography (r = 0.55, p less than 0.005) and echocardiography (r = 0.43, p less than 0.025). The sum of T/R-wave ratios, the RV6/RV5 ratio and the Romhilt-Estes score were predictors of LV end-diastolic volume, as determined by angiography (r = 0.83, p less than 0.001) and echocardiography (r = 0.77, p less than 0.005). Total 12-lead QRS amplitude and the sum of T/R-wave ratios were the only independent predictors of LV mass, either angiographically (r = 0.81, p less than 0.001) or echocardiographically measured (r = 0.71, p less than 0.025). It is concluded that a single electrocardiographic criterion for prediction of LV morphology in patients with IDC is barely effective. Multiple electrocardiographic criteria should be utilized to better predict LV mass and distinguish reliably between LV wall thickening and dilatation.

GATA repeats in the genome of Asellus aquaticus (Crustacea, Isopoda)

A 500 bp fragment of Drosophila genomic DNA containing 37 copies of the tetranucleotide GATA was used to probe, by Southern DNA blotting and in situ hybridization, two natural populations of the isopod crustacean Asellus aquaticus collected from the Sarno and Tiber rivers. This species does not have a recognizable sex chromosome pair. In a number of males from the Sarno population chromomycin A3 staining reveals a heteromorphic chromosome pair. The heterochromosome has two blocks of heterochromatin. After digestion of genomic DNA with six restriction endonucleases and hybridization with the GATA probe, the two populations exhibit different fragment length patterns. No sex-linked pattern was observed in either population. In situ hybridization to chromosomes of males and females from the Sarno population does not reveal any sex-specific pattern of labelling and indicates a scattered distribution of GATA sequences on most chromosomes with some areas of preferential concentration. The heterochromatic areas of the male heterochromosome are not labelled.

Natural history of hypertrophic cardiomyopathy in the elderly

To assess the natural history of hypertrophic cardiomyopathy (HC) in the elderly, we reviewed clinical, electrocardiographic and hemodynamic data from 21 patients over 60 years of age at diagnosis who were studied since 1970. Comparison with 95 younger patients (less than 60 years) showed that a greater proportion of older patients had exertional angina and atrioventricular conduction delay at time of diagnosis. During a mean follow-up of 9 +/- 6 years, mortality from cardiac causes was 33% (7 out of 21) in patients over 60 years of age and 23% (22 out of 95) in younger patients (NS). Univariate analysis showed that functional class and hemodynamic indices of right- and left-sided heart impairment were associated with a poor prognosis in the elderly. We conclude that: (1) presenting features and outcome of patients with HC over 60 years of age do not differ significantly from those of younger patients; (2) functional class and measurements of cardiac function are significant predictors of death in the elderly.

Hypertrophic cardiomyopathy: long-term effects of propranolol versus verapamil in preventing sudden death in "low-risk" patients

The aim of this study was to evaluate retrospectively the outcome of 101 patients who were assigned to long-term therapy with propranolol (55 patients) or verapamil (46 patients) between 1980 and 1988. Baseline clinical, electrocardiographic, and echocardiographic data were similar in both groups. Exclusion criteria were the evidence of complex ventricular arrhythmias, a family history of the disease and/or sudden death, previous syncopal episodes, or left ventricular dysfunction. During a mean follow-up of 4 +/- 3 years (range: 1-9 years), side effects were more commonly recorded in patients who were treated with verapamil rather than in propranolol-treated patients (8 vs. 3, respectively), though the difference was not statistically significant. Sixteen patients (13 propranolol-treated patients and three verapamil-treated ones, p less than 0.05) died suddenly while on treatment. In addition, three patients who stopped verapamil because of adverse reactions died from heart failure after withdrawal, but before the end of the follow-up period. The assessment of total mortality on the intention-to-treat basis showed that death due to cardiac causes occurred in 13 propranolol-treated patients and in six verapamil-treated patients (ns). Thus, verapamil was more effective than propranolol in preventing sudden death during long-term therapy of "low-risk" patients with hypertrophic cardiomyopathy, though its administration was associated with the occurrence of non-sudden cardiac deaths and a high incidence of side effects.

Relation of complex ventricular arrhythmias to presenting features and prognosis in dilated cardiomyopathy

To evaluate whether complex ventricular arrhythmias relate to presenting features and prognosis of dilated cardiomyopathy, 104 patients were studied from 1977 to 1987. At diagnosis, the 19 patients with complex ventricular arrhythmias (18%), as compared to the 85 patients without (82%), had a higher incidence of palpitation (P less than 0.01), severe dyspnea (P less than 0.001) and atrial fibrillation (P less than 0.01). They showed also higher mean right atrial pressures (10 +/- 5 vs 6 +/- 4 mm Hg, P less than 0.001) and higher right ventricular end-diastolic pressures (11 +/- 4 vs. 7 +/- 4 mm Hg, P less than 0.001) than patients without complex ventricular arrhythmias. Histologic samples were collected from the 32 patients (31%) studied since 1984 and semiquantitatively graded. The 11 patients with complex ventricular arrhythmias showed a higher frequency of severe interstitial fibrosis than the 21 patients without (64% vs. 24%, P less than 0.05), but they were otherwise similar as to the frequency of marked myocellular hypertrophy, changes of myocardial regression, endocardial fibrosis, attenuation of myocytes, hyperplasia of smooth muscle cells and infiltration by inflammatory cells. During a follow-up of 3.8 +/- 3.5 years, 35 patients (34%) died. Mortality was 58% (11 out of 19) in patients with complex ventricular arrhythmias and 28% (24 out of 85) in patients without (P less than 0.025). These results show that complex ventricular arrhythmias in dilated cardiomyopathy are associated with impairment of function of the right heart and severe interstitial fibrosis of the left ventricle, rather than with left ventricular dysfunction. Presence of complex ventricular arrhythmias also seems to identify those at high risk for death.

Acute effects of nifedipine versus isosorbide dinitrate on exercise tolerance in patients with isolated coronary artery occlusion and collaterals

The acute effects of slow-release nifedipine and isosorbide dinitrate on exercise tolerance were compared in nine patients with isolated total coronary artery occlusion showing retrograde filling via collaterals. All patients had a reproducible positive exercise stress test off medication before the study. Each patient was randomized to 10 mg slow-release nifedipine and 5 mg isosorbide dinitrate in a single-blind, cross-over study. The exercise stress test was performed 30 minutes after drug administration. After nifedipine, three patients had a negative exercise stress test, whereas the test was negative after isosorbide dinitrate only in one patient. A significantly higher exercise tolerance was detected at peak exercise after nifedipine than after isosorbide dinitrate, as shown by a longer exercise time (380 +/- 44 vs. 295 +/- 41 seconds, p less than 0.001), a more increased maximum work load (355 +/- 89 vs. 255 +/- 55 W x min, p less than 0.02), and a higher rate-pressure product (30,300 +/- 2,500 vs. 26,100 +/- 2,700, p less than 0.01). In conclusion, these results seem to suggest that nifedipine may have a vasomotor effect on collaterals, since it elevated the threshold of ischemia more than isosorbide dinitrate did in patients with isolated coronary artery occlusion, showing retrograde filling via collaterals.

Electrocardiographic findings in patients with hypertrophic cardiomyopathy. Relation to presenting features and prognosis

The relation of ECG findings to presenting features and prognosis was evaluated in 125 consecutive patients with hypertrophic cardiomyopathy (HC). Seventy-nine men and 46 women (mean age, 34 +/- 7 years) were studied since 1970. Most ECG features were similar in patients with and without a left ventricular outflow tract gradient. Those with obstruction had a higher prevalence of left ventricular hypertrophy according to ECG voltage criteria (54% vs. 28%, p less than 0.01), whereas higher grade ventricular arrhythmias were more common in patients without an outflow gradient (20% vs. 7%, p less than 0.05). The prevalence of ECG abnormalities was also similar in younger (less than or equal to 14 years) and older patients (greater than 14 years), and only repolarization abnormalities were more frequently detected in the older age group (56% vs. 32%, p less than 0.025). Stratification of patients according to the clinical state revealed that those who had moderate to severe functional limitation had a higher prevalence of atrial fibrillation than asymptomatic or mildly symptomatic patients (24% vs. 1%, p less than 0.001). There were no significant differences in most hemodynamic variables among patients dichotomized according to any specific ECG abnormality. Only patients with atrial fibrillation had significantly higher right ventricular end-diastolic pressure (10 +/- 7 vs. 6 +/- 4 mmHg, p less than 0.01), lower systolic index (22 +/- 8 vs. 37 +/- 15 ml/m2; beat, p less than 0.02) and lower ejection fraction (53 +/- 8 vs. 64 +/- 10%, p less than 0.001) than those in sinus rhythm.(ABSTRACT TRUNCATED AT 250 WORDS)