[Update on infectious endocarditis]

Although one of the oldest known cardiac disease, infectious endocarditis (IE) remains a subject of constant change from epidemiological, diagnostic and therapeutic points of view. In the epidemiological field, the main feature is the increasing incidence of IE due to streptococcus bovis. Representing a quarter of cases in France, this type of IE is particularly frequent in the elderly and underlying colonic disease should be investigated. In the diagnostic field, the progress of methods of microbiological identification has been considerable, especially in molecular (PCR) and histological diagnosis which are particularly useful in IE with negative blood cultures. From the prognostic point of view, the role of echocardiography has recently been emphasised not only for diagnosis but also for prognosis and for predicting the embolic risk. The longest vegetations (>10 or 15 mm) are associated with a greater risk not only of embolism but also in terms of prognosis. The recent recommendations of the French Society of Cardiology recall the main surgical indications in IE and include a new indication of echocardiography.

[A multicentre trial of the diagnostic value and cost of electrocardiography in symptoms suggesting arrhythmia with a new event recorder with transtelephonic transmission]

Events recorders are used for electrocardiographic documentation of symptoms of arrhythmia too sporadic and short lasting to be recorded by 24 hour Holter monitoring. However, there are no French studies comparing the value and cost of event recorders with conventional diagnostic methods. Recently, a new telediagnostic device has become available in France leading to an assessment of the technique. The aim of this study was to determine the value of this event recorder and the cost of diagnostic ECG in the assessment of presumed arrhythmic symptoms such as palpitations or rare tachycardia (<3 episodes per week) of short duration, compared with conventional techniques. Fifty-eight patients with these criteria were randomised, 30 to Survcard (Group I) and 28 to conventional diagnostic methods (Group II). The patients were comparable with respect to age, sex distribution, type of symptoms and associated cardiac disease. The ECG diagnosis of the symptoms was established in 20 cases (66.6%) of patients in Group I in 17 +/- 16 days, and in 14 cases (50.0%) of Group II in 23 +/- 28 days. The difference between the two groups was not statistically significant. The cost of a positive diagnosis for Group I (Survcard) varied from 0 to 228.47 Euro with an average of 71.22 +/- 117.02 Euro. The cost of positive diagnosis in Group II varied from 76.80 to 2340.41 Euro with an average of 480.39 +/- 797.41 Euro. In conclusion, this study showed that the percentage of patients with a positive diagnosis was comparable in the two groups but that the cost was 6 times higher in the group investigated by conventional methods than in the Survcard group because of more costly medical intervention.

[Quantification of valvular regurgitation by the convergence zone method]

The convergence zone method is currently used routinely to quantify valvular regurgitation, particularly mitral insufficiency, but also aortic and tricuspid regurgitation. It is quick to perform, requires relatively little training and remains valid in the presence of atrial fibrillation and in the association of regurgitation-stenosis. It relies on the measurement of output at the level of an isovelocity hemisphere and allows calculation of the regurgitant orifice surface (SOR) and the regurgitant volume per beat (VR). It is reserved for severe regurgitation corresponding to angiographic grade 4: SOR > 40 mm2 and VR > 60 ml for mitral insufficiency, SOR > 30 mm2 and VR > 60 ml for aortic insufficiency, and SOR > 40 mm2 and VR > 40 ml for tricuspid insufficiency.

[Isolated non-compaction of the left ventricle]

Isolated non compaction of the left ventricle is a rare congenital cardiomyopathy linked to an arrest of normal myocardial embryogenesis. We report two cases of isolated non compaction of the left ventricle discovered by echocardiography in 2 males of 30 and 55 years. The first had progressively worsening cardiac insufficiency, the second was being followed for an unexplained cardiomyopathy. In both cases, the diagnosis was able to be confirmed by transthoracic echocardiography, supported by MRI data. Although present from birth, this condition can become apparent at various ages and is complicated by sudden death (principal cause of mortality), severe cardiac insufficiency, or thrombo-embolic accidents. The diagnosis of left ventricular non compaction should be considered when faced with unexplained cardiac insufficiency in the adult.

[Mitral insufficiency related to a spasm of the left anterior descending artery. A case report]

We report the case of a female patient of 76 years old admitted to our hospital for a pre-operative assessment of a symptomatic mitral regurgitation (MR) whose transthoracic echocardiography revealed only a trivial regurgitation. The occurrence during hospital stay of an acute pulmonary edema contemporary to the occurrence of a huge MR permitted to suspect the diagnosis of a paroxystic ischemic MR. Angiographic and hemodynamic evaluation revealed only a non-significant atheromateous plaque located in the distal LAD. The infusion of Methylergometrine triggered a severe spasm at the site of that plaque, associated with a huge MR visualized by TTE with restricted movements of both leaflets, responsible for an acute pulmonary edema occurring on the table of the catheterization laboratory. Recovery was quickly obtained after intravenous injection of Nitroglycerin, which removed the spasm and valvular regurgitation. The diagnosis of paroxystic ischemic mitral regurgitation was confirmed and a treatment based on high dosage of calcium-blocker was decided. After a follow-up of more than one year, the patient remains asymptomatic and the regurgitation has never occurred.

Comparison of clinical and echocardiographic characteristics of Streptococcus bovis endocarditis with that caused by other pathogens

The aim of our study was to compare the clinical, echographic, and prognostic features of Streptococcus bovis (S. bovis) endocarditis with those caused by other streptococci and pathogens in a large sample of patients with definite endocarditis by Duke criteria, using transesophageal echocardiography. Two hundred six patients (149 men, mean age 57 +/- 15 years) with a diagnosis of infective endocarditis formed the study population. All patients underwent multiplane transesophageal echocardiography and blood cultures. Cerebral, thoracoabdominal computed tomographic scan was performed in almost all patients (95%). All patients with S. bovis endocarditis underwent colonoscopy. Incidence of S. bovis endocarditis in our sample was 19%. Patients with S. bovis endocarditis were older than other groups. Multiple valve involvement, native valves, and large vegetations (>10 mm) were more frequent in patients with S. bovis. There was a significantly higher occurrence of embolism in the S. bovis group. Splenic embolism and multiple embolisms were significantly more frequent in patients with S. bovis. Gastrointestinal lesions, anemia, and spondylitis were observed more frequently with S. bovis endocarditis. In addition to the requirement for gastrointestinal examination for S. bovis endocarditis, our study underlines the need for systematic screening for vertebral and splenic localizations, and suggests the use of early surgery to prevent the high risk of embolism in these patients.

Very long-term survival and durability of mitral valve repair for mitral valve prolapse

BACKGROUND

Mitral regurgitation (MR) due to mitral valve prolapse (MVP) is often treatable by surgical repair. However, the very long-term (>10-year) durability of repair in both anterior leaflet prolapse (AL-MVP) and posterior leaflet prolapse (PL-MVP) is unknown.

METHODS AND RESULTS

In 917 patients (aged 65+/-13 years, 68% male), surgical correction of severe isolated MR due to MVP (679 repairs and 238 replacements [MVRs]) was performed between 1980 and 1995. Survival after repair was better than survival after MVR for both PL-MVP (at 15 years, 41+/-5% versus 31+/-6%, respectively; P=0.0003) and AL-MVP (at 14 years, 42+/-8% versus 31+/-5%, respectively; P=0.003). In multivariate analysis adjusting for predictors of survival, repair was independently associated with lower mortality in PL-MVP (adjusted risk ratio [RR] 0.61, 95% CI 0.44 to 0.85; P=0.0034) and in AL-MVP (adjusted RR 0.67, 95% CI 0.47 to 0.96; P=0.028). The reoperation rate was not different after repair or MVR overall (at 19 years, 20+/-5% for repair versus 23+/-5% for MVR; P=0.4) or separately in PL-MVP (P=0.3) or AL-MVP (P=0.3). However, the reoperation rate was higher after repair of AL-MVP than after repair of PL-MVP (at 15 years, 28+/-7% versus 11+/-3%, respectively; P=0.0006). From the 1980s to the 1990s, the RR of reoperation after repair of AL-MVP versus PL-MVP did not change (RR 2.5 versus 2.7, respectively; P=0.58), but the absolute rate of reoperation decreased similarly in PL-MVP and AL-MVP (at 10 years, from 10+/-3% to 5+/-2% and from 24+/-6% to 10+/-2%, respectively; P=0.04).

CONCLUSIONS

In severe MR due to MVP, mitral valve repair compared with MVR provides improved very long-term survival after surgery for both AL-MVP and PL-MVP. Reoperation is similarly required after repair or replacement but is more frequent after repair of AL-MVP. Recent improvement in long-term durability of repair suggests that it should be the preferred mode of surgical correction of MVP whether it affects anterior or posterior leaflets and is an additional incentive for early surgery of severe MR due to MVP.

Contrast echocardiography improves the accuracy and reproducibility of left ventricular remodeling measurements: a prospective, randomly assigned, blinded study

OBJECTIVES

We sought to assess the impact of contrast injection and harmonic imaging, on the measure by echocardiography of left ventricular (LV) remodeling.

BACKGROUND

Left ventricular remodeling is a precursor of LV dysfunction, but the impact of contrast injection and harmonic imaging on the accuracy or reproducibility of echocardiography is unclear.

METHODS

We prospectively collected LV images by using simultaneous methods. Then, LV volumes were measured off-line, in blinded manner and in random order. The accuracy of echocardiography was determined in comparison to electron beam computed tomography (EBCT) in 26 patients. The reproducibility of echocardiography was assessed by three blinded observers with different training levels in 32 patients.

RESULTS

End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF), as measured by EBCT (195 +/- 55, 58 +/- 24 and 137 +/- 35 ml and 71 +/- 5%, respectively) and echocardiography with harmonic imaging and contrast injection (194 +/- 51, 55 +/- 20 and 140 +/- 35 ml and 72 +/- 4%, respectively), showed no differences (all p > 0.15) and excellent correlations (all r > 0.87). In contrast, echocardiography using harmonic imaging without contrast injection underestimated the EBCT results (all p < 0.01). Reproducibility was superior with rather than without contrast injection for intraobserver and interobserver variabilities (all p < 0.001). Values measured by different observers were different without contrast injection, but were similar with contrast injection (all p > 0.18). Consequently, intrinsic patient differences represented a larger and almost exclusive proportion of global variability with contrast injection for EDV (94 vs. 79%), ESV (93 vs. 82%), SV (87 vs. 53%) and EF (84 vs. 41%), as compared with harmonic imaging without contrast injection (all p < 0.005).

CONCLUSIONS

For assessment of LV remodeling, echocardiography with harmonic imaging and contrast injection improved the accuracy and reproducibility, as compared with imaging without contrast injection. With contrast injection, variability was almost exclusively due to intrinsic patient differences. Therefore, when evaluation of LV remodeling is deemed important, assessment after contrast injection should be the preferred echocardiographic approach.

Echocardiography predicts embolic events in infective endocarditis

OBJECTIVES

The aim of our study was to assess the value of transesophageal echocardiography (TEE) in predicting embolic events (EEs) in a large group of patients with definite endocarditis according to the Duke criteria, including silent embolism.

BACKGROUND

The value of echocardiography in predicting embolism in patients with endocarditis remains controversial. Some studies reported an increased risk of embolism in patients with large and mobile vegetations, whereas other studies failed to demonstrate such a relationship.

METHODS

Multiplane transesophageal echocardiograms of 178 consecutive patients with definite infective endocarditis (IE) were analyzed. The incidence of embolism was compared with the echocardiographic characteristics (localization, size and mobility) of the vegetations. To detect silent embolism, cerebral and thoraco-abdominal scans were performed in 95% of patients.

RESULTS

Among 178 patients, 66 (37%) had one or more EEs. There was no difference between patients with and without embolism in terms of age, gender and left valve involved. On univariate analysis, Staphylococcus infection, right-side valve endocarditis and vegetation length and mobility were significantly related to EEs. A significant higher incidence of embolism was present in patients with vegetation length >10 mm (60%, p < 0.001) and in patients with mobile vegetations (62%, p < 0.001). Embolism was particularly frequent among 30 patients with both severely mobile and large vegetations (> 15 mm) (83%, p < 0.001). On multivariate analysis, the only predictors of embolism were vegetation length (p = 0.03) and mobility (p = 0.01).

CONCLUSIONS

Our study shows that the presence of vegetations on TEE is predictive of embolism and that the morphologic characteristics of vegetations are helpful in predicting EEs in both mitral and aortic valve IE. It also suggests that early operation may be recommended in patients with vegetations > 15 mm and high mobility, irrespective of the degree of valve destruction, heart failure and response to antibiotic therapy.

[Mitral valve insufficiency and surgical repair]

Management of mitral regurgitation have benefited over the last 10 years from the better understanding of its natural history and from the advent of new echocardiographic quantitative methods. The dismal prognosis displayed by patients with flail leaflet and severe mitral regurgitation medically treated in one hand and the demonstration of the dramatic consequences of impaired pre-operative left ventricular function in the other, have been a strong incentive for early surgical correction of the disease. In the same time, mitral valve repair developed because of the improvement in the surgical techniques, of changes in aetiology and because of the widespread use of intra-operative transoesophageal echocardiography. Mitral repair has been shown to be an independent and beneficial predictor of overall survival, operative mortality and late survival and consequently became the support of early surgical strategies. But it is not the only factor to predict mortality and morbidity, and one must not forget the decisive and independent part played by age, preoperative symptoms and above all pre-operative left ventricular function. Therefore, mitral valve repair must not be considered as a pretext to postpone intervention but should be an other reason to intervene earlier.

Value and limitations of the Duke criteria for the diagnosis of infective endocarditis

OBJECTIVES

The purpose of this study was to assess the value and limitations of Duke criteria for the diagnosis of infective endocarditis (IE).

BACKGROUND

Duke criteria have been shown to be more sensitive in diagnosing IE than the von Reyn criteria, but the diagnosis of IE remains difficult in some patients.

METHODS

Both classifications were applied in 93 consecutive patients with pathologically proven IE. Blood cultures, and transthoracic and transesophageal echocardiography were performed in all patients.

RESULTS

Sensitivities for the diagnosis of IE were 56% and 76% for von Reyn and Duke criteria, respectively. Fifty-two patients were correctly classified as "probable IE" by von Reyn and "definite IE" by Duke criteria (group 1). However, discrepancies were observed in 41 patients. Eleven patients (group 2) were misclassified as "rejected" by von Reyn, but were "definite IE" by Duke criteria; this difference could be explained by negative blood cultures and positive echocardiogram in all patients. In eight patients (group 3), the diagnosis of IE was "possible" by von Reyn but "definite" by Duke criteria. This difference was essentially explained by the failure of the von Reyn classification to consider echocardiographic abnormalities as major criteria. Twenty-two patients (group 4) were misclassified as possible IE using Duke criteria, being false negative of this classification. Echocardiographic major criteria were present in 19 patients, but blood cultures were negative in 21 patients. The cause of negative blood cultures was prior antibiotic therapy in 11 patients and Q-fever endocarditis diagnosed by positive serology in three cases.

CONCLUSIONS

Twenty-four percent of patients with proved IE remain misclassified as "possible IE" despite the use of Duke criteria, especially in cases of culture-negative and Q-fever IE. Increasing the diagnostic value of echographic criteria in patients with prior antibiotic therapy and typical echocardiographic findings and considering the serologic diagnosis of Q fever as a major criterion would further improve the clinical diagnosis of IE.

[Heart perforation following transvenous implantation of a cardiac pacemaker]

OBJECTIVES

We studied the incidence, clinical signs and severity of heart perforations occurring after transvenous pacemaker implantation.

PATIENTS AND METHODS

A series of 16 consecutive cases of heart perforation observed in one cardiac pacing unit from 1989 to 1998 were reviewed.

RESULTS

Heart perforation occurred after implantation in 9 cases; the verall incidence for all lead implantation was 0.57%. The ventricle was perforated in 6 cases, the atrium in 1, and an undetermined site in 2 cases. Active fixation was involved in 5 cases, passive fixation in 4. A bipolar lead was used in 7 cases and a unipolar lead in 2. Heart perforation occurred after prior external stimulation in 7 cases, including one case with tamponnade requiring emergency pericardial drainage after implantation. Repositioning the lead in the ventricle was sufficient in 6 cases and a thoracotomy for an atrial wound was performed in 1 case. Difficulties in right ventricular catheterism due to kyphoscoliosis in elderly subjects was found to be a risk factor.

CONCLUSION

Heart perforation following transvenous pacemaker implantation is an exceptional complication with currently used material. Tamponnade is extremely rare. Besides verifying the mechanical performance of the leads, prevention requires a rigorous protocol for catheterism and wall fixation.

[Infectious endocarditis, did it change?]

Although the incidence and prognosis of infectious endocarditis have remained relatively stable for many years, this disease has recently undergone major modifications of its aetiological and bacteriological profiles, and has benefited from progress in echocardiographic techniques. New diagnostic criteria have been proposed and considerable therapeutic progress has been accomplished, in both medical (antibiotic therapy) and surgical (conservative surgery, homografts) modalities.