Is dobutamine stress echocardiography predictive of middle and late term outcomes in mitral stenosis patients?

AIM

In mitral stenosis (MS) patients with a poor symptom-echocardiography correlation, dobutamine stress echocardiography (DSE) still does not have a confirmed utility and predictive value. Our aim is to evaluate usefulness of DSE in assessing 2 and 5 years clinical outcomes.

METHODS

Forty-four consecutive patients with known MS were submitted, between April 1998 and July 1999, to basal and DSE. Patients were divided in 2 groups: group A if during DSE was reached a mean mitral gradient (MG) = or > 15 mmHg and/or a pulmonary arterial pressure (PAP) = or > 60 mmHg, and group B if MG and/or PAP were respectively lower than 15 and 60 mmHg. Endpoints considered were death, hospitalization for acute pulmonary edema, complications associated with mitral valve disease and mitral valve interventions (percutaneous or surgical). Mean follow-up was 73.6+/-16.6 months.

RESULTS

Mean age was 55.2+/-10.5 years; 83.7% were women; NYHA class was I-II-III respectively in 18.6%, 58.1% and 23.3% of the patients; mean mitral valve area was 1.39+/-0.26 cm2; mean MG 8.05+/-2.54 mmHg; PAP 39.3+/-7.9 mmHg. Twenty-five patients met criteria for group A and 18 for group B. The event-free interval (27.9+/-32.1 months in group A vs 53.5+/-25.8 months in group B; P=0.008) and the 2 years event-free survival (40% for group A vs 88.9% for group B; P=0.002) showed significantly different patterns between the 2 groups. The 5 years survival analysis did not reach significance.

CONCLUSION

DSE seems to detect MS patients that will have rapid evolution of their valvular disease within 24 months.

Severe degenerative aortic stenosis: when a senile patient is a candidate for surgery

Senile aortic stenosis is characterized by calcific degeneration of the valve that prevents the full opening of the cusps in systole. The disease may be silent for many years despite the presence of severe flow obstruction and generally is associated with aortic regurgitation and calcification of the coronary arteries. The continuous increase of the aged population with aortic stenosis entails difficult decisions in selecting the candidates for aortic valve replacement in order to optimize the timing for surgery. Although clinical examination is still fundamental for the diagnosis of the disease and the screening of the population, noninvasive assessment by Doppler echocardiography has transformed the management of these patients. The procedure allows better identification of patients who may benefit from valve replacement in particular in the setting of a ''low output/low gradient'' state and permits a follow-up of the progression of the disease in patients who are not yet candidates for surgery. It also allows a decrease in the utilization of invasive hemodynamics becoming a cost benefit tool for the health system. When performed properly, it is relatively time consuming, needs experience but offers major anatomic and hemodynamic data. Under these circumstances, cardiac catheterization is required only in cases when there is discordance between the clinical assessment and cardiac ultrasound evaluation. In this review we summarize the prevalence and significance of the disease in the elderly population and the use of all recent echocardiographic data that may help select the true candidates for surgery.

The Myocardial Performance Index detects chronic cardiac allograft dysfunction sooner than other methods

AIM

Many noninvasive techniques have been proposed for the early detection of chronic heart graft dysfunction. Diastolic dysfunction may precede systolic dysfunction, and often is prominent; therefore, the aim of the study was to investigate the clinical and prognostic value of a Doppler-derived index of both systolic and diastolic function in heart transplanted patients (Myocardial Performance Index, MPI).

METHODS

The MPI was measured in 63 consecutive patients (mean age 55 years, 49 men and 14 women) in sinus rhythm with an orthotopic heart transplantation for at least 1 year (mean 5.3 years) and in 63 age and sex-matched controls. A complete clinical examination was performed at the time of enrollment and was repeated after 3 months.

RESULTS

At 3 months, 11 patients (17.5%) presented events (heart failure, hospitalisation or cardiac death). Patients were divided into 2 groups: Group A (52 patients) without events in the follow-up and Group B (11 patients) with events. The values of MPI in Group B (0.55+/-0.19) were significantly higher than values in Group A (0.34+/-0.18, P=0.001). Whereas the values of the index did not differ significantly between Group A and control group (0.34+/-0.18 vs 0.33+/-0.10, P=NS). In the univariate analysis, the population of heart transplanted patients was dichotomised in subgroups by a cut-off MPI of 0.47 and a cut-off ejection fraction (EF) of 50%. Nine patients (41%) with MPI=or>0.47 presented events, while only 2 patients (5%) with MPI<0.47 had any event (P<0.001; c2 12.9). Six patients (85%) with EF<50% had events, while only 5 patients (9%) with EF=or>50% had an event (P<0.001; c2 14). In the multivariate analysis only MPI (chi squared=22.6, P=0.018) and EF (chi squared=20.8, P=0.025) were significant independent predictors of heart failure or cardiac death. By looking at Kaplan-Meyer curves, MPI seems to be better than EF in the earlier detection of graft dysfunction.

CONCLUSION

MPI, as a combined systolic and diastolic index, may detect graft dysfunction earlier than EF.

Contrast enhanced imaging of left internal mammary artery after vasodilation improves the evaluation of the bypass graft

AIM

The aim of the study is to evaluate patency and flow reserve by echocardiography in arterial grafts using the left internal mammary artery (LIMA) to the left anterior descending coronary artery (DA). The main limitations in performing this study routinely are the weakness of the Doppler signal and the exact chest localization of the graft. The purposes of the study were: to verify the feasibility of the echo color Doppler method on LIMA; to verify which between the parasternal or supralavicular view is the better approach to obtain a clear signal; to verify the increase of systolic and diastolic flow velocity of LIMA in basal conditions and after infusion of dipyridamole, and if the visualization of the Doppler signal improves after contrast infusion.

METHODS

Twenty patients (all males, mean age 63+/-7.8 years) with previous coronary artery bypass in the last 10 years, and without any significant stenosis in the left mammary artery graft as proved by a recent coronary angiogram (within 6 months), were selected for our study. LIMA was evaluated by two echocardiographic approaches. Patients were studied at rest and after pharmacological infusion of dipyridamole using the protocol of 0.56 mg/kg in 4 minutes. Contrast enhancement was infused in order to improve the Doppler signal using Levovist contrast agent at rest and after vasodilatation. Diastolic and systolic peak flow velocities, their ratio and the diastolic and total velocity time integrals were evaluated.

RESULTS

The results showed that using the supraclavicular approach we obtained the visualization of the graft at rest in all patients (100%) and using the parasternal approach in 19 out of 20 (95%) even without contrast injection. At rest, the diastolic and systolic peak flow velocities were 0.417+/-0.133 m/s and 0.368+/-0.1291 m/s; their ratio (diastolic/systolic) was 0.882+/-0.7362. The overall and diastolic velocity time integrals were 0.1571+/-0.0645 m and 0.2232+/- 0.0701 m. After dipyridamole infusion we observed in all patients an increase in diastolic and systolic peak flow velocities as expected by 0.582+/-0.342 m/s (p<0.005) and 0.73+/-0.427 m/s (p<0.005). Contrast injection at rest and after peak dipyridamole infusion showed a better and clearer Doppler signal of the graft allowing an easier evaluation of the velocity curves in all patients. In fact using the association dipyridamole-Levovist the velocity ratio and the total and diastolic velocity time integral values were 1.268+/-0.368 (p<0.05), 0.3492+/-0.131 m (p<0.05) and 0.2309+/-0.153 m (p<0.05).

CONCLUSION

In conclusion, this new echo-color-Doppler approach seems to be valid for the evaluation of the patency rate and flow reserve of the internal mammary artery graft, and helps to better select patients who really need angiography.

When should asymptomatic patients with combined severe aortic stenosis and aortic insufficiency undergo valve replacement? A clinical case

Indications to prosthetic aortic valve implantation in patients with aortic stenosis or aortic regurgitation or both stenotic or regurgitant aortic valve, who present without symptoms, are controversial. We present the case of an asymptomatic patient with combined severe aortic stenosis and an equally important insufficiency, undergoing surgery for valve substitution with a bileaflet prosthesis. After surgery he was treated with warfarin according to the doses recommended and underwent follow-up with clinical and echocardiographic exams. Eight months after intervention the patient had an embolic stroke with aphasia and right hemiplegia, despite the therapeutic level of INR. At present, even though he has partly recovered motor function, he reports a noteworthy decline in life quality, because of the persistent speech difficulties. We use this case as the starting point for a discussion of the chance of referring patients affected by aortic valvulopathy to valve substitution, in the absence of symptoms.

Cardiopulmonary exercise testing and exhaled nitric oxide in the assessment of patients with mitral stenosis

AIM

In patients with mitral stenosis, symptoms do not always correlate with echocardiographic data. The aims of the study were to evaluate the role of cardiopulmonary exercise testing in the assessment of patients with mitral stenosis and to quantify nitric oxide production at rest and at the end of exercise.

METHODS

We evaluated 43 patients with moderate to severe mitral stenosis with a discrepancy between echocardiographic data and symptoms. Nitric oxide output was calculated by measuring nitric oxide concentration in the exhaled air at rest and at the end of exercise test.

RESULTS

Patients were divided in 2 groups: group 1 with a functional capacity <75% at cardiopulmonary exercise test (VO2max in % of the predicted one) and group 2 with functional capacity >75%. Transvalvular gradient and pulmonary artery pressure were significantly higher in group 1 than in group 2 (respectively 9.07 +/- 2.11 mmHg vs 6.01 +/- 1.08 mmHg, p<0.001 and 42.8 +/- 7.2 mmHg vs 33.1 +/- 4.7 mmHg, p<0.001). Patients of group 1 had a lower nitric oxide output at the end of exercise compared to group 2 (231.4 +/- 96.6 nl/min vs 326.3 +/- 74.0 ml/min, p=0.01) and to normal subjects (511.15 +/- 180.1 nl/min, p<0.001).

CONCLUSION

Cardiopulmonary exercise testing provides objective non invasive information in the evaluation of patients with discrepancy between symptoms and echocardiographic data. Different levels of nitric oxide output during exercise suggest the role of nitric oxide in regulating pulmonary vascular tone.

Transoesophageal echocardiography in patients without arterial and major cardiac sources of embolism: difference between stroke subtypes

We studied the records of 175 consecutive patients referred to our neurologic ward between January 1994 and February 2000 with a diagnosis of ischaemic cerebrovascular disease (ICVD) (stroke or transient ischaemic attack - TIA) who underwent transoesophageal echocardiography (TEE). We excluded patients with large vessel disease, high-risk embolic cardiopathies and other rare causes of stroke. According to clinical and neuroimaging findings, patients were divided into two groups. The lacunar (LAC) group (69/175 (39.4%)) and the nonlacunar (N-LAC) one (106/175 (60.6%)). The control population consisted of 78 consecutive patients, referred to the echocardiography laboratory for TEE without history of ICVD and known heart disorders. Patent foramen ovale (PFO) frequency was significantly higher in case patients than in control subjects (55/175 (31.4%) vs. 13/78 (16.6%); p = 0.02). Among case patients, PFO was more prevalent in the N-LAC group than in the LAC one (43/106 (40.6%) vs. 12/69 (17.4%); p = 0.0005). A large degree of shunt occurred in 53.5% of N-LAC patients and in 16.7% of LAC ones (p = 0.04). Atrial septal aneurysm (ASA) was detected in 12% of case patients and 1.3% of control subjects (p = 0.003) and was more frequent in the N-LAC group than in the LAC one (16 vs. 5.8%; p = 0.05). Mitral prolapse (MP) was present in 6/175 (3.4%) ICVD patients (vs. 1/78 among controls) in most cases associated with myxomatous valve redundancy. Aortic arch atheromas (AA) were detected in 12% of ICVD patients and in 10.2% of controls. The frequency was 9.4% in N-LAC and 15.9 in LAC. No complicated AA (plaque thickness >4 mm, ulcerated atheroma, superimposed thrombus) were detected. After multivariate analysis, PFO (OR = 3.8; 95% CI = 2.7-7.9) and ASA (OR = 8.01; 95% CI = 3.0-16.1) appeared to be independent predictors of ICVD. PFO (OR = 2.24; 95% CI = 1.24-4.92) was also independently associated with N-LAC stroke subtype and its importance was even higher in younger patients. Our study provides further evidence that TEE is a helpful diagnostic tool in stroke patients without arterial and major cardiac sources of embolism. However, its utility differs according to type and localization of the ischaemic lesion being more relevant in patient with N-LAC infarctions.

[A case of pulmonary thromboembolism after interruption of treatment with unfractionated heparin]

Pulmonary embolism is a quite frequent event (incidence 1/10000/year), and blood stasis, endothelial lesions and coagulation disorders are predisposable factors. Elective treatment is heparin, but the use of this medication is associated with a possible ipercoagulative rebound effect. The case presented is a patient with unstable angina treated with heparin infusion, who developed pulmonary embolism after discontinuation of heparin treatment; the patient didn't present a genetic coagulopathy. Others risk factors have been analyzed and it was observed that discontinuation of heparin infusion could have a predominant role in the development of thrombosis. A MedLine research on the rebound effect of heparin and how to reduce it has been carried out.

[Evaluation and management of patients with mitral valve stenosis]

A review of the guidelines of the American College of Cardiology and the American Heart Association for the management of patients with valvular heart disease, published in 1998, is presented. The therapeutical advances introduced during the past decade, percutaneous mitral balloon valvotomy and surgical ablation of atrial fibrillation, have modified the therapeutical approach to patients with mitral stenosis. In this article some controversial aspects are examined with a review of the recent literature. The definition of "valve morphology favorable for percutaneous balloon valvotomy", which is based on echocardiographic examination, is still debatable. Different echocardiographic scores published until now are reported. Some patients, who have no or mild symptoms, develop irreversible pulmonary hypertension: in order to avoid this complication early interventional procedure is suggested, but only in those patients at low post-procedural risk. In symptomatic patients, NYHA class II/III, with atrial fibrillation it is possible to consider a conservative surgical approach combined to crioablation of atrial fibrillation. The possibility of maintaining sinus rhythm and avoiding anticoagulation leads to a revaluation of surgical repair as option to valve replacement and percutaneous mitral balloon valvotomy.

[Functional assessment of mitral stenosis]

The following parameters must be taken into account when assessing the severity of mitral stenosis: symptoms, objective examination, electrocardiogram, chest X-ray, a simple exercise test with or without cardiopulmonary test, echocardiography and lastly a hemodynamic test. Differences are often observed between the clinical and instrumental findings. In these cases a major contribution is made by the use of physical effort in response to both ECG and heart catheterization in order to quantify the patient's functional deficiency and valve response. The latter aspect must be validated using a simultaneous comparison between echocardiography and the hemodynamic test and longitudinal clinical studies.

[Ischemic cardiovascular diseases. Correlation with Helicobacter pylori infection]

Coronary heart disease is the primary cause of mortality in western countries. The well-established ("classical") risk factors cannot fully explain epidemiological variations of this disease. From several years infections have been linked to ischemic vascular events and recent studies pointed to the role of Helicobacter pylori (H. pylori), a spiral Gram negative bacterium, that chronically infects human stomach and is involved in the pathogenesis of gastritis and peptic ulceration. Systematic reviews of studies have suggested the existence of a possible weakly positive association between this bacterium and coronary heart disease, but this could be due to confounding bias and influenced by the degree of investigations heterogeneity. Experiments from animal studies demonstrated that H. pylori infection in mice induces the formation of platelet aggregates and in contrast to Chlamydia pneumoniae it has not been found in the plaque: therefore, the role of H. pylori, could be even more important in the acute phase of myocardial infarction. There is the need for extensive prospective studies to evaluate the incidence of these diseases in relation to the presence of H. pylori infection. Appropriately randomized studies employing an antibiotic treatment for patients affected by ischemic vascular disease will answer the question of whether H. pylori has a causal role in the pathogenesis of acute myocardial infarction and ischemic stroke.

Ischemic cardiovascular disease and Helicobacter pylori. Where is the link?

Coronary heart disease (CHD) is the leading cause of death in western countries. Although several major risk factors have been identified, they fail to account for all the epidemiological variants of the disease, thus warranting research into novel causal agents. Cardiovascular diseases have long been associated with chronic infections acting through the activation of inflammatory pathways, and antibiotic therapy has been shown to produce a dramatic decrease in the rate of disease recurrence in patients with a history of myocardial infarction or unstable angina. The link between Helicobacter pylori (H. pylori) infection and CHD, first described by Mendall et al. in 1994, has been the subject of a multitude of epidemiological and clinical studies; however, these have been so heterogeneous that not two of them are based on a comparable selection of patients and focused on the same kind of disease, e.g. stable coronary heart disease or acute myocardial infarction. Evidence from animal studies supports the thesis that H. pylori plays an extremely important role in the acute phase of myocardial infarction: the bacterium causes platelet aggregation and induces pro-coagulant activity in experimentally infected mice. H. pylori may also contribute to atherosclerosis through an auto-immune process against endothelial cells or an increased concentration of homocysteine in the blood due to decreased levels of folic acid and cobalamin. The exact role of H. pylori cannot yet be fully assessed: there is a clear and present need for further studies with appropriate epidemiological and clinical approaches to investigate through prospective and interventional trial the possible causal relationship between H. pylori and CHD.

[Use of colchicine in chronic pericardial effusion. Presentation of 2 clinical cases and review of the literature]

Colchicine was introduced in 1987 for the treatment of recurrent pericarditis. Up to the present, papers have been published on a total of 117 patients treated with colchicine after the failure of treatment with FANS, corticosteroids and repeated pericardiocentesis. Here two cases of chronic pericardial effusion, one secondary to pericardiotomy, the second idiopathic, are reported. Both were recalcitrant to conventional therapy. Both patients were treated with 2 mg/die colchicine for 1 month followed by 1 mg/die for a further 5 months, without recurrence of the effusion after follow-up of 12 and 24 months respectively. No side-effects were observed. Colchicine is an anti-inflammatory drug which, by inhibiting various leukocyte functions, depresses the action of the leukocytes and of the fibroblasts at the site of the inflammation. We conclude that colchicine is effective in post-pericardiotomic and idiopathic chronic pericardial effusion as already reported in cases of recurrent pericarditis. Given the lack of side-effects, it could be considered as a drug of choice alternatively to FANS and corticosteroids.

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.

Activity of GH/IGF-I axis in patients with dilated cardiomyopathy

OBJECTIVE

There is evidence showing that GH and IGF-I have specific receptors in the heart and that these hormones are able to promote cardiac remodelling and inotropism. It has been reported that patients with dilated cardiomyopathy (DCM) benefit from treatment with rhGH showing a striking increase in cardiac contractility. However, until now, the activity of GH/IGF-I axis in DCM has never been clearly assessed.

PATIENTS

To clarify this point, we enrolled 39 patients with idiopathic or post-ischaemic DCM (36 M/3 F; age (mean +/- S.D.) 55.3 +/- 9.0 years; BMI: 25.3 +/- 3.2 kg/m2; New York Heart Association class (NYHA) I/2, II/19, III/15, IV/3) and 42 age-matched controls (CS, 38 M/4 F; age 56.0 +/- 7.8 years; BMI: 24.9 +/- 1.5 kg/m2). DCM patients were characterized by a left-ventricular diastolic diameter of 73.8 +/- 8.3 mm, a shortening fraction of 15.9 +/- 6.4% and a left ventricular ejection fraction of 25.1 +/- 8.7%. In all subjects clinical and biochemical indices of renal and hepatic function as well as nutritional parameters were in the normal range.

MEASUREMENTS

In both groups we studied: a) IGF-I levels in basal conditions and after administration of low rhGH doses for 4 days (5.0 or 10.0 mu/kg/day x 4 days); b) the acute GH-response to GHRH (1.0 mu/kg i.v.) or hexarelin (HEX, 2.0 mu/kg i.v.), a peptidyl GH secretagogue (GHRP); c) mean GH concentration (mGHc) over 10 h sampling (every 20 min) from 2200 h to 0800 h.

RESULTS

Basal IGF-I levels in DCM were lower (P = 0.000039) than in CS (135.2 +/- 46.8 vs. 193.7 +/- 63.7 mu/l), whereas, basal IGFBP-3 and GHBP2 levels in DCM and CS were similar (2.5 +/- 1.3 vs. 2.6 +/- 0.5 mg/l and 25.3 +/- 3.6 vs. 28.3 +/- 5.0%; P = 0.95 and P = 0.085, respectively). After 4 days of 5.0 mu/kg/day rhGH administration, IGF-I levels in DCM (215.4 +/- 82.0 mu/l; P = 0.0023 vs. baseline) remained lower (P = 0.027) than those in CS (280.0 +/- 80.7 mu/l; P = 0.000080 vs. baseline). After 10.0 mu/kg/day for 4 days, IGF-I levels in DCM (297.2 +/- 109.2 mu/l; P = 0.0033 vs. baseline) were similar (P = 0.76) to those in CS (310.9 +/- 81.7 mu/l; P = 0.000060 vs. baseline). The GH response to GHRH in DCM was lower (P = 0.0022) than that in CS (hAUC0-120: 192.0 +/- 177.3 vs. 345.3 +/- 191.1 mu/l/h) whereas that to HEX in DCM and CS was similar (611.0 +/- 437.5 vs. 535.4 +/- 302.8 mu/l/h; P = 0.95). Within the DCM group, basal and rhGH-stimulated IGF-levels as wel as the GH response to GHRH or HEX were not different among NYHA classes and did not show any correlation with ECHO parameters. The mGHc in DCM (1.0 +/- 0.5 mu/l) was similar (P = 0.57) to that in CS (0.9 = 0.7 mu/l).

CONCLUSIONS

Our present data demonstrate that in dilated cardiomyopathy patients with severe left ventricular dysfunction basal IGF-I levels are reduced whereas the IGF-I response to low rhGH doses is preserved. These findings suggest a normal peripheral GH sensitivity in dilated cardiomyopathy. On the other hand, though nocturnal mean GH concentration in dilated cardiomyopathy patients is similar to that in normal subjects, the somatotroph responsiveness to GHRH, but not that to hexarelin, is reduced. Thus, subtle alterations in the activity of GH/IGF-I axis are present in dilated cardiomyopathy.

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.

[The superior vena cava obstruction syndrome after the implantation of a permanent pacemaker: a clinical case report]

Occlusion of the superior vena cava is a rare but serious complication of transvenous endocardial pacing. We describe 1 case of superior vena cava obstruction associated with permanent transvenous DDD pacemaker, following local infection. Thrombolytic therapy was initially effective, resulting in relief of signs of obstruction. However systemic infection occurred 3 months later. The patient was subsequently submitted to surgical removal of the infected pacemaker apparatus. Several therapeutical options described in previous papers are reviewed: anticoagulants, thrombolytics, percutaneous dilatation, surgical removal of the catheter. In conclusion, when a chronic process induced by local infection is present, surgical treatment is the best therapeutical approach.

Fixed subaortic stenosis associated with hypertrophic cardiomyopathy: report of a rare familial occurrence

INTRODUCTION

Fixed subaortic stenosis is considered to be an acquired condition. It is often associated with congenital heart disease, creating a turbulence in the left ventricle outflow tract. Familial forms of fixed subaortic stenosis are very unusual. We report a remarkable familial cluster in which fixed subaortic stenosis is associated with hypertrophic cardiomyopathy.

METHODS

Fourteen relatives of a patient affected with hypertrophic cardiomyopathy and fixed subaortic stenosis underwent cardiological examination, electrocardiogram and echo-doppler study.

RESULTS

Two of the proband's sisters showed an association between asymmetrical hypertrophic cardiomyopathy and fixed subaortic stenosis. The brother presented a subaortic ridge and concentric left ventricular hypertrophy. The other members of the family (another brother and the third-generation relatives) were unaffected.

CONCLUSIONS

While the association between fixed subaortic stenosis and hypertrophic cardiomyopathy has commonly been reported, there is little in the literature to suggest the family-related nature of this association. The familial occurrence of this association reveals genetic transmission, with a recessive autosomal pattern of inheritance. This finding goes against the usual autosomal dominant pattern of inheritance in hypertrophic cardiomyopathy. Familial studies of FSS are needed in order to gain a better understanding of the genetic background of these patients.

[Hypertrophic obstructive cardiomyopathy in a patient with Turner syndrome]

A case of hypertrophic obstructive cardiomyopathy in a patient with Turner syndrome is reported. The most frequently associated cardiac anomalies are coarctation of the aorta and bicuspid aortic valve. Hypertrophic cardiomyopathy has never been reported in this syndrome but is frequent in Noonan syndrome. In these two conditions the phenotype may be indistinguishable but the cariotype is different: normal in Noonan and 45X in Turner syndrome. Our patient had the typical somatic features, and the cariotype was 45X in all examined cells. A familial form of hypertrophic cardiomyopathy was excluded by the normal clinical examination of other members of the family. The presence of hypertrophic cardiomyopathy also in Turner syndrome and the recent localization on the long arm of the chromosome 12 of the gene for Noonan syndrome might postulate a common pathogenesis of the two syndromes.

Mitral annulus size in isolated mitral stenosis

M-mode and two-dimensional echocardiographic images were obtained using the planimeter method in the short axis view and calculated by Doppler-derived pressure half-time in 24 patients with mitral stenosis before and after surgical commissurotomy and posterior annuloplasty. The diameter of the mitral valve annulus was measured in the standard long axis view and in the apical four-chamber view using two-dimensional echocardiography. Preoperatively, the mitral annulus was dilated in all patients as a consequence of left atrial dilation. This could be one of the factors causing residual regurgitation after surgical mitral commissurotomy. However, more data are needed to demonstrate that annuloplasty can prevent the development of mitral regurgitation after surgery.

[Another case of dissecting aortic aneurysm with familial incidence]

Several authors have reported aortic dissection in Marfan's syndrome with familial incidence. Cases of dissecting aortic aneurysms have likewise been described in families whose members had severe systemic arterial hypertension. We report 4 cases of familial aortic aneurysm, 3 of whom had a dissection, in the absence of Marfan's phenotype but with histologic findings and genetic transmission similar to those previously described as formes frustes of Marfan's syndrome.

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).

[ Bacterial endocarditis of the pulmonary valve damaged by thoracic radiotherapy (in Hodgkin's disease)]

It is well known that radiation therapy to the anterior mediastinum may induce lesions of all cardiac structures. The pericardium is most frequently involved, but atrioventricular conduction disorders, cardiomyopathy, coronary stenosis may also be produced. Aortic, mitral and tricuspid lesions have been described. However, clinical evidence of pulmonic valve involvement has not been reported. Only at necropsy has fibrotic thickening of the pulmonic cusps occasionally been found. We report a case of infective endocarditis of the pulmonic valve in a 53-year-old patient who had undergone thoracic radiation therapy for Hodgkin's disease 31 years previously. Four years prior to the endocarditis he had also been submitted to myocardial revascularisation for critical lesions of the left main and right coronary ostia, and to aortic valve replacement because of stenosis and insufficiency. At that time, the pulmonic valve was fibrotic on echo examination. It is noteworthy that, of all the cardiac valves, the infective process involved only the pulmonic one, which is seldom the target of an infection. To our knowledge this is the first case of bacterial endocarditis of a heart valve that had been previously damaged by radiation therapy.

Relation between spontaneous atrial fibrillation and atrial vulnerability in patients with Wolff-Parkinson-White pattern

An intracavitary electrophysiological study was carried out on 103 patients with Wolff-Parkinson-White (WPW), 23 symptomatic patients had documented episodes of atrial fibrillation, 54 symptomatic patients had atrioventricular reentrant tachycardias, and 26 asymptomatic. Patients were examined for the relation between spontaneous atrial fibrillation and atrial vulnerability, defined as the possibility to induce sustained (greater than 1 minute) episodes of atrial fibrillation with a stimulation protocol excluding atrial bursts. Atrail fibrillation induction was attempted by single and double atrial extrastimuli during pacing at two different cycle lengths and incremental atrial pacing. Sustained atrail fibrillation was induced in 65% of the patients with spontaneous atrial fibrillation, and in 13% of the symptomatic patients with documented episodes of atrioventricular reentrant tachycardias and in 15% of the asymptomatic patients (P less than 0.0005). Atrial vulnerability was higher in patients with spontaneous atrial fibrillation than in patients without this arrhythmia. No significant difference was observed between symptomatic without atrial fibrillation and asymptomatic patients.

[Induction of atrial tachyarrhythmia in patients with Wolff-Parkinson-White syndrome with and without spontaneous atrial fibrillation]

The purpose of this study was to examine the relation between spontaneous atrial fibrillation and the induction of atrial tachyarrhythmias during electrophysiologic study in patients with Wolff-Parkinson-White, with and without atrial fibrillation. Intracavitary electrophysiologic study was performed on 115 patients, 27 with spontaneous atrial fibrillation (group 1), 57 symptomatic due to AV re-entrant tachycardias, without spontaneous atrial fibrillation (group 2) and 31 asymptomatic (group 3). Induction of atrial fibrillation was attempted by using single and double atrial extrastimuli during atrial pacing at 2 different cycle lengths and by incremental atrial pacing (protocol A). When atrial fibrillation was not obtained, atrial bursts were added (protocol B). Atrial fibrillation or flutter were induced in 81% of group 1.54% of group 2 and 55% of group 3 patients (p less than 0.05), using protocol A. They were induced in 100, 75 and 71%, respectively (p = 0.01), with protocol B. Considering only sustained (greater than 1 minute) episodes, atrial fibrillation or flutter were induced in the three groups with protocol A in 74, 33 and 32% of the patients, respectively (p less than 0.001). The difference in the three groups was even greater when atrial fibrillation was considered separately from atrial flutter. The reason for this was that atrial fibrillation was induced in two thirds of group 1 patients, while only about 15% of patients without spontaneous atrial fibrillation had this arrhythmia induced. Our results suggest that the induction of sustained atrial fibrillation is a useful parameter to separate Wolff-Parkinson-White patients with from those without spontaneous atrial fibrillation. Due to the low specificity of the analysis of the shortest R-R interval during induced atrial fibrillation for the identification of the patients at risk of sudden death, the induction of sustained atrial fibrillation could be proposed as an additional parameter. This would improve the specificity of electrophysiologic study.

Stress and pharmacologic tests as methods to identify patients with Wolff-Parkinson-White syndrome at risk of sudden death

Noninvasive stress and pharmacologic tests with procainamide and propafenone were studied as methods to identify patients with Wolff-Parkinson-White syndrome (WPW) who would otherwise be judged at risk of sudden death on the basis of electrophysiologic criteria: the shortest RR interval during induced atrial fibrillation less than or equal to 250 ms or accessory pathway anterograde effective refractory period less than or equal to 250 ms. Sixty-five patients were studied. Twenty-four patients fulfilled the electrophysiologic risk criteria (group A) and 41 patients fulfilled none of these criteria (group B). Persistence of preexcitation during stress test showed a sensitivity of 96% and a specificity of 17% to identify group A patients; its positive predictive value was 40% and negative predictive value 88%. With both procainamide and propafenone tests persistence of preexcitation identified group A patients with a sensitivity of 96% and a specificity of 51%; their positive and negative predictive value were, respectively, 53 and 95%. Stress and pharmacologic tests have good sensitivity and negative predictive value, but low specificity and positive predictive value.

Congenital long QT syndrome inducing 2:1 atrioventricular block: early detection in fetal life

A case is reported of congenital long QT interval associated with fixed 2:1 atrioventricular block. The bradycardia was detected at 16 weeks of gestational age. The atrioventricular block was due to an extremely delayed ventricular repolarization. Early detection of bradycardia in fetal life and the demonstration of a normal positive correlation between QT duration and ventricular rate suggest that, in this case, the syndrome may be due to an anomaly of the myocardial cells rather than to imbalance of the sympathetic nervous system.

[Ebstein's anomaly in adults]

Eighteen patients (11 women and 7 men) with Ebstein's anomaly recognized in adult age (18-55 years, mean 31.5) were followed in our Department for 3-13 years (mean 7 years). Echocardiographic and cardiac catheterization studies were performed in the majority. Clinical and echocardiographic findings were evaluated in the follow-up period. During the first assessment mild cyanosis was present in 14 cases. Nine patients were in NYHA class I, 6 in NYHA class II, 2 in NYHA class III and 1 in NYHA class IV. Eleven patients complained of palpitations. A Wolff-Parkinson-White (WPW) syndrome was present in 4 cases. At cardiac catheterization, done in 14 patients, a moderate-severe tricuspid regurgitation was found in 7 patients. In 8 cases there was a mild right-to-left shunt at atrial level. During the follow-up period there was 1 sudden death. In all patients with the WPW syndrome, the symptoms were well controlled by medical treatment. Systemic embolism was a major complication in 3 patients (all with patent foramen ovale and right-to-left shunt). During the follow-up period surgery was performed in 3 patients for a worsening of the tricuspid incompetence. Good early and late results were obtained in all 3 patients. The clinical conditions remained stable in the other 14 cases. Seven women out of 11 had 1 or more pregnancies (all together 14 pregnancies). In conclusion, in our experience Ebstein's anomaly diagnosed in adult life is a benign and stable disease, particularly if the patient is asymptomatic; surgical correction must be performed if the patient becomes symptomatic either because of paradoxical embolism or because of worsening of the tricuspid regurgitation.

[Torsade de pointes following intravenous infusion of amiodarone]

A case of intravenous amiodarone induced QT-interval prolongation and ventricular arrhythmia of the torsade de pointes type is described: the arrhythmia developed in the presence of hypokalemia. The efficacy of lidocaine in suppressing this type of arrhythmia is reported. The electrophysiologic effects of intravenous and oral amiodarone administration are compared.

[Electrophysiologic study in supine and upright positions in patients with Wolff-Parkinson-White syndrome]

It is well known that in patients with Wolff-Parkinson-White (W.P.W.) adrenergic activity stimulation induced by exercise or isoproterenol I.V. infusion shortens the anterograde effective refractory period (E.R.P.) of the accessory pathway. Our purpose was to evaluate whether the upright position produces similar changes on the electrophysiologic properties of the accessory pathway and influences reciprocating tachycardias induction. In 18 patients, with W.P.W. syndrome, who underwent electrophysiologic study, we determined the anterograde E.R.P. of the accessory pathway and attempted to induce a reciprocating tachycardia in the supine and in the upright position. In 13 patients (72%) the anterograde E.R.P. of the accessory pathway shortened in the upright position (303 +/- 104 msec vs 331 +/- 123 msec; p less than 0.001); in 4 patients (22%) it was unchanged; in 1 patient was not defined, being inferior to the atrium E.R.P. We were able to induce a reciprocating tachycardia in 3 patients in the supine position, in 6 patients in the upright position. Electrophysiologic testing in the upright position improves the evaluation of the accessory pathway electrophysiologic properties.

Atrioventricular block complicating amiodarone-induced hypothyroidism in a patient with pre-excitation and rate-dependent bilateral bundle branch block

As a clinical entity atrioventricular (AV) block due to hypothyroidism is rare. Such a case induced by hypothyroidism complicating long-term therapy with amiodarone in a 45 year old woman with pre-excitation is presented. Electrophysiologic data obtained before and during thyroxine replacement therapy showed that hypothyroidism lengthens the effective refractory period of the atria, AV node, bypass tract and His-Purkinje system (that in the ventricle not being measured); this lengthening resembles the effects of long-term administration of amiodarone. These observations suggest that depressed thyroid function may be protective against arrhythmias but a patient with preexisting conduction system disease may develop AV block. The tendency to develop AV block in a patient who is euthyroid was reduced by bypass tract conduction. These findings are significant not only in monitoring amiodarone effects during chronic prophylactic drug therapy but also in providing further insight into the complex interrelation between the action of the drug and the thyroid hormones on cardiac muscle.

[Ion channels in cardiac tissue. Validity and limits of cellular electrophysiology in the interpretation of clinical data]

New experimental methods in cellular electrophysiology allowed the identification and characterization of specific "ion channels" in the plasma membrane of cardiac cells in different regions of the heart. Function and implication of the "ion channels" have been considered in 1) the initiation of the heart-beat, 2) the chronotropic and inotropic effects of neurotransmitters (nor-epinephrine-acetylcholine), 3) the action mechanism of the steroid cardioactive drugs, 4) the cardiac repolarization, 5) the physiopathology of several arrhythmias. Moreover clinical data useful for the indirect evaluation of the ion channels function have been pointed out, stressing the ion channels models contribution for the cardiac pathology interpretation, particularly in the cardiac arrhythmias field.

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.

[The tricuspid valve in carcinoid cardiopathy: characteristic echocardiographic aspects]

Cardiac involvement is commonly seen in the carcinoid syndrome (C.S.). However echocardiographic observations in this condition are still very scanty. In two patients with the C.S. and clinical signs of tricuspid insufficiency (plus mild pulmonic stenosis in one case) two-dimensional echocardiography showed: 1) right ventricular overload with normal left heart valves and chambers; 2) a peculiar aspect of the tricuspid valve, whose three leaflets were markedly thickened and retracted. The anterior leaflet was almost fixed in a semi-open position while the septal and posterior leaflets appeared as rigid structures fixed in an open position, extending from the annulus into the right ventricular cavity. In both cases only the posterior cusp of the pulmonary valve could be visualized. The afore-mentioned changes exactly reproduce the pathological features of the tricuspid valve in the carcinoid heart disease and so far, have not been observed in other conditions.

[Amiodarone in paroxysmal supra-ventricular tachycardias associated with sinus bradycardia]

The efficacy of amiodarone in the prevention of atrial tachycardia is well recognised. However, there remains some controversy over its use in patients with a basal sinus bradycardia because of the risk of further depression of sinus node function. We studied the effects of acute and chronic amiodarone therapy in 13 patients with paroxysmal supraventricular tachycardia and intercritical sinus bradycardias of between 40 and 50/min. All patients underwent electrophysiological investigation under basal conditions and after 5 mg/kg IV amiodarone. Five patients were excluded from chronic oral amiodarone therapy after IV amiodarone for the following reasons : sinus bradycardia of less than 30/min; sinus node recovery times greater than 2 s; 2nd or 3rd degree sino-atrial block. The other 8 patients were administered oral amiodarone on a long term basis. They were followed up clinically with dynamic ECGs every three months over a period of 1 to 3 years. All symptoms regressed in 6 patients. In one patient, the daily attacks of palpitations decreased to one a week. One patient did not improve. No cases of sino-atrial standstill were observed, although the sinus rate remained unchanged. The results of our study show that amiodarone may be administered for long periods in patients with sinus bradycardia and attacks of paroxysmal supraventricular tachycardia if the dynamic ECG during the waking hours shows a heart rate of no less than 40/min, and if electrophysiological investigations do not show significant depression of sinus node function after acute intravenous administration of the drug.

Left ventricular emptying dynamics in patients with asymmetric septal hypertrophy and concentric hypertrophic cardiomyopathy

We studied the dynamics of left ventricular (LV) emptying in 8 patients with asymmetric septal hypertrophy (ASH), 6 patients with concentric hypertrophic cardiomyopathy (CHC), and 6 normal controls. Four patients with ASH had resting systolic gradients greater than 20 mmHg, all had significant post premature ventricular contraction (PVC) systolic pressure gradients. LV volume (V) was obtained by frame-by-frame analysis of cineangiograms. End-diastolic volume was similar for all groups; end-systolic volume was significantly less in ASH and CHC patients than in normals. Maximum dV/dt was similar in ASH and CHC, and significantly greater than normals. Total systolic contraction time (SCT), i.e., time from peak volume to last cine frame at minimum volume, was similar for all groups, but the time required to eject 90% of stroke volume (90%T), as a fraction of SCT, was shorter for ASH (0.52 +/- 0.07) and CHC patients (0.51 +/- 0.05) than normals (0.67 +/- 0.07) (p less than 0.05 vs myopathy groups). In the sinus beat following a PVC, however, this ratio decreased significantly in normals and CHC patients, but did not change in ASH patients. We conclude that ASH and CHC have similar exaggerated systolic LV ejection dynamics in the basal state; the failure of ASH patients with post-PVC systolic outflow gradient to reduce 90% T/SCT post PVC may reflect obstruction to LV emptying.