Rest perfusion abnormalities in hypertrophic cardiomyopathy: correlation with myocardial fibrosis and risk factors for sudden cardiac death.

AIM: To measure the prevalence of abnormal rest perfusion in a population of consecutive patients with known hypertrophic cardiomyopathy (HCM) referred for cardiovascular MRI (CMR), and to assess any associations between abnormal rest perfusion and the presence, pattern, and severity of myocardial scar and the presence of risk factors for sudden death. MATERIALS AND METHODS: Eighty consecutive patients with known HCM referred for CMR underwent functional imaging, rest first-pass perfusion, and late gadolinium enhancement (LGE). RESULTS: Thirty percent of the patients had abnormal rest perfusion, all of them corresponding to areas of mid-myocardial LGE and to a higher degree of segmental hypertrophy. Rest perfusion abnormalities correlated with more extensive and confluent LGE. The subgroup of patients with myocardial fibrosis and rest perfusion abnormalities (fibrosis+/perfusion+) had more than twice the incidence of episodes of non-sustained ventricular tachycardia on Holter monitoring in comparison to patients with myocardial fibrosis and normal rest perfusion (fibrosis+/perfusion-) and patients with no fibrosis and normal rest perfusion (fibrosis-/perfusion-). CONCLUSIONS: First-pass perfusion CMR identifies abnormal rest perfusion in a significant proportion of patients with HCM. These abnormalities are associated with the presence and distribution of myocardial scar and the degree of hypertrophy. Rest perfusion abnormalities identify patients with increased incidence of episodes of non-sustained ventricular tachycardia on Holter monitoring, independently from the presence of myocardial fibrosis.

Magnetic resonance angiography virtual endoscopy in the assessment of pulmonary veins before radiofrequency ablation procedures for atrial fibrillation.

Magnetic resonance angiography (MRA) is a safe and non-invasive imaging method that can readily depict the pulmonary veins (PV), whose imaging has acquired momentum with the advent of new techniques for radiofrequency ablation of atrial fibrillation (AF). We evaluated whether virtual endoscopy from 3D MRA images (MRA-VE) is feasible in studying the morphology of PV. Fifty patients with AF underwent pre-ablative MRA (1.5 T). Images were acquired with axial T-2 weighted and 3D-SPGR sequences after intravenous administration of Gd-DTPA and automatic triggering. Postprocessing was performed by an experienced radiologist with maximum intensity projection (MIP) and virtual endoscopy software (Navigator, GEMS). The venoatrial junction was visualized with MRA-VE in 49 of 50 patients (98.0%). Twenty-seven patients (55.1%) had two ostia on both sides, 13 patients (26.5%) had two ostia on the right and a single common ostium on the left, 5 patients (10.2%) had accessory PV and 4 patients (8.2%) had both an accessory right PV and a single common ostium on the left. Flythrough navigation showed the number and spatial disposition of second-order PV branches in 48 out of 49 patients (98.0%). MRA-VE is an excellent tool for at-a-glance visualization of ostia morphology, navigation of second-generation PV branches and easy endoluminal assessment of left atrial structures in pre-ablative imaging.

The molecular mechanisms of angiogenesis: a new approach to cardiovascular diseases.

Although the role of new blood vessel formation in cancer and its development have been well documented, the strategy to manipulate angiogenesis in order to restore blood flow in the ischemic myocardium, a novel form of therapy currently undergoing clinical trials, has received less attention. Recent advances in our understanding of the stimuli and of the control mechanisms regulating the development of new blood vessels in coronary heart disease have led to an improved picture of the compensatory healing process that accompanies myocardial ischemia and infarction. However, we have to remind that, together with life- and tissue-saving effects, the angiogenetic process might alter the natural course of the consequences and organ manifestation of arterial diseases as in the atherosclerotic plaque. The purpose of this review is to provide an overview on the molecular mechanisms involved in the angiogenetic process. Angiogenesis during ontogenesis, neoangiogenesis (adult new vessel formation), arteriogenesis and the related regulators will be analyzed. Moreover, the role of neoangiogenesis in plaque development and instability will be discussed. Due to the introductory nature of this review and the large number of studies on neovascularization in ischemic limbs this topic has been omitted.

A large false aneurysm of the right ventricle within a giant epicardial lipoma.

Lipomas, which account for approximately 10% of all neoplasms of the heart, may be detected in asymptomatic patients by chance during echocardiography, CT scan, or MRI scan. Occasionally, lipomas are complicated by arrhythmias. We describe a patient who presented with severe cardiomegaly and paroxysmal supraventricular tachycardia. An MRI scan showed a large intrapericardial lipoma with two large cavities inside communicating with each other and with the right ventricular chamber through a defect of the right ventricular wall. The mass was partially removed, and the right ventricle was patched. Surgery combined with antiarrhythmic therapy resulted in a good short-term result.

Mitral valve prolapse. Comparison between valvular repair and replacement in severe mitral regurgitation.

BACKGROUND: The aim of this study was to analyse long term results of mitral valve repair of degenerative mitral regurgitation compared to valve replacement. METHODS: A hundred-twenty-five consecutive patients with severe mitral valve insufficiency who underwent cardiac surgery from January 1987 to December 1995 were included in the study. Mean age was 55+/-16 years (77 males, 48 females). Mitral repair was performed in 62 patients and mitral valve was replaced in 63 patients. Mean follow-up was 5 years. The repair procedures were based on quadrangular resection of the posterior leaflet, chordal replacement and transposition. Annuloplasty was performed in 100% of cases. The technique of valve replacement was conventional with complete excision of the valve in the majority of cases. RESULTS: Operative mortality following valve repair was 1.6%, no death occurred in the prosthesic group. In the repair group overall survival and re-operation rate were respectively 95.2% and 6.5%, while in the replacement group were 93.7% and 7.9%. No endocarditis and thromboembolic accidents were observed following valvuloplasty, while in the prostheses 6.3% of patients had endocarditis and 1.6% had a thromboembolic event. Mild or moderate left ventricular dysfunction was present in 5 patients after valvuloplasty and in 9 patients with prostheses. CONCLUSIONS: Considering these results we conclude that, in patients with severe degenerative mitral insufficiency, mitral valve repair is warranted whenever it is possible. The advantages given by maintaining the native valve suggest that surgery should be considered in asymptomatic patients before the occurrence of the left ventricular dysfunction.

[Percutaneous transluminal coronary angioplasty for postinfarction residual ischemia: mid- and long-term results]. / Angioplastica coronarica transluminale percutanea per l'ischemia residua postinfartule: risultati a medio e lungo termine.

Aim of this study was to assess the long-term results of PTCA in patients with a recent myocardial infarction. The study population consisted of 244 consecutive patients who underwent a PTCA < or = 30 days after myocardial infarction either because of angina (116 patients), or because of provoked ischemia (62 patients), or in the absence of both (66 patients). "Simple" balloon angioplasty, without adjunctive devices, was performed. Most of the patients were seen at 1 year intervals at the outpatient clinic; otherwise information was gathered either from the family physician or by telephone. The following events were noted during a follow-up of 6-102 months (median 39 months): death, myocardial infarction, need for re-PTCA or surgical revascularization, recurrence of angina. Survival and event-free curves were calculated according to the method of Kaplan and Meier; statistical comparisons between the curves were obtained by the log-rank test. Periprocedural deaths, infarctions and surgical revascularizations are included in the actuarial curves. Differences were examined between patients with Q and non-Q wave infarctions, single vessel versus multivessel disease, left ventricular ejection fraction > or 50% versus < 50%. A clinical success was achieved in 85% of the procedures. Sixteen patients were lost at follow-up. Overall, within the first 30 days and during follow-up, 12 (4.9%) patients died, 19 (7.7%) suffered from myocardial infarction, 34 (13.9%) required re-PTCA or surgical revascularization, and 63 (25.8%) experienced angina again.(ABSTRACT TRUNCATED AT 250 WORDS)

Spontaneous beat-to-beat variability of the ventricular repolarization duration.

The spontaneous beat-to-beat variability of the ventricular repolarization duration was investigated in 21 healthy subjects (age 25-71 years; mean, 40 years) during the basal state in a recumbent position. For each subject, approximately 1,000 consecutive cycles were analyzed with an automated technique. The time series of the RR, QT, and RT intervals generate histograms that approximate normal distributions and have mean standard deviations of 57.0 ms, 5.4 ms, and 4.3 ms, respectively. Spectral analysis was used to detect rhythmical oscillations in these time series. The power spectra densities of both heart rate and ventricular repolarization during show peaks in the same frequency bands: low frequency (0.05-0.12 Hz) and high frequency (0.2-0.4 Hz). The power distribution between these two bands observed in the ventricular repolarization duration spectra was found to be the reverse of that in heart rate spectra (p less than 0.005).

Contour detection of the left ventricular cavity from angiographic images.

A knowledge-based heuristic method is proposed to outline the left ventricular cavity from end-diastolic angiographic images in right anterior oblique projection in man. The algorithm search for the optimal path in a weighted graph, representing the state space, can implicitly be defined as the set of all the contour segments that can be produced by successor operators. Applications to routine images are presented.

Electrocardiographic and electrophysiologic features of dual pathways within the His bundle.

Electrophysiological evidence of dual intrahisian pathways has been shown in a patient with diseased His bundle. The main electrocardiographic features, in this case were: 1). 1:1 A-V conduction with alternating short and long PR intervals; 2). unexpected A-V Wenckebach sequences; and 3). unexpected interruption of Wenckebach sequences by early captures of the ventricles with short and fixed PR intervals. These features were due to the following causes: 1). different E.P. properties of the two pathways producing a shift of conduction from a fast conducting pathway (FCP) to a slow conducting pathway (SCP); 2). a concealed reentry from the SCP into the FCP; and 3). a phase of "unexpected conduction" in the FCP.

Bedside evaluation of atrioventricular block with narrow QRS complexes: usefulness of carotid sinus massage and atropine administration.

Second-degree intra-His bundle block is frequently of type I (Wenckebach periods) or 2:1. In this situation, the surface electrocardiogram does not permit distinction between intranodal (atrioventricular [A-V] and subnodal (intra-His) block. This study examined the value of bedside carotid sinus massage and atropine administration in diagnosing the site of block from the standard electrocardiogram in subjects with chronic A-V block and narrow QRS complexes. Fifteen patients had intra-His bundle block and 10 had intranodal block. The combination of two tests correctly located the site of block in 22 subjects, and was noncontributory in 3. Thirteen of the 15 intra-His bundle blocks and 9 of the 10 intranodal blocks were properly identified; in three cases the results were nondiagnostic, but no wrong diagnoses were made. The noninvasive bedside method of carotid sinus massage and the use of atropine permit both the localization and the determination of the type of block in the majority of cases of second degree A-V block and narrow QRS complexes. In a proper clinical context they can obviate the need for invasive electrophysiologic studies.

Atypical 2nd degree AV block due to bilateral bundle branch block with Wenckebach phenomenon and concealed conduction in the bundle branch system.

A case of bilateral bundle branch block is described with the following features: -- 2nd degree infranodal AV block due to bilateral, intermittently synchronous "phase 3" bundle branch block; -- occasional AV conduction failure due to concealed His bundle extrasystoles; -- right bundle branch block pattern due to retrograde activation from the left bundle branch; -- QRS complexes having normal duration due to uniform slow conduction in both bundle branches; -- Wenckebach phenomenon in the right bundle branch; -- concealed conduction in both branches. The above interpretations are based on the use of His bundle recordings, results of right atrial stimulation and of pharmacological testing. Determinations of the lengths of all H--H intervals, whether H was followed by a ventricular response or blocked, permitted insight into the mechanism of 2nd degree AV block with varying (right and left) bundle branch block.