Stefan Illien

Silent and apparent cerebral embolism after retrograde catheterisation of the aortic valve in valvular stenosis: a prospective, randomised study

BACKGROUND In most patients, severity of valvular aortic stenosis can be accurately assessed non-invasively by echocardiography. However, retrograde catheterisation of the aortic valve is often undertaken. This procedure has a potential risk of neurological complications, with an unknown incidence of clinically silent embolism. We aimed to establish the frequency of clinically apparent and silent cerebral embolism after this procedure. METHODS We prospectively randomised 152 consecutive patients with valvular aortic stenosis at a German university hospital to receive either cardiac catheterisation with (n=101) or without (n=51) passage through the aortic valve. Patients underwent cranial MRI and neurological assessment within 48 h before and after the procedure to assess cerebral embolism. Controls were 32 patients without valvular aortic stenosis who underwent coronary angiography and laevocardiography. FINDINGS 22 of 101 patients (22%) who underwent retrograde catheterisation of the aortic valve had focal diffusion-imaging abnormalities in a pattern consistent with acute cerebral embolic events after the procedure; three of these patients (3%) had clinically apparent neurological deficits. By contrast, none of the patients without passage of the valve, or any of the controls, had evidence of cerebral embolism as assessed by MRI. INTERPRETATION Patients with valvular aortic stenosis who undergo retrograde catheterisation of the aortic valve have a substantial risk of clinically apparent cerebral embolism, and frequently have silent ischaemic brain lesions. Patients should be informed about these risks, and this procedure should be used only in patients with unclear echocardiographical findings when additional information is necessary for clinical management.

D-Ribose improves diastolic function and quality of life in congestive heart failure patients: a prospective feasibility study

Patients with chronic coronary heart disease often suffer from congestive heart failure (CHF) despite multiple drug therapies. D‐Ribose has been shown in animal models to improve cardiac energy metabolism and function following ischaemia. This was a prospective, double blind, randomized, crossover design study, to assess the effect of oral D‐ribose supplementation on cardiac hemodynamics and quality of life in 15 patients with chronic coronary artery disease and CHF. The study consisted of two treatment periods of 3 weeks, during which either oral D‐ribose or placebo was administered followed by a 1‐week wash out period, and then administration of the other supplement. Assessment of myocardial functional parameters by echocardiography, quality of life using the SF‐36 questionnaire and functional capacity using cycle ergometer testing was performed. The administration of D‐ribose resulted in an enhancement of atrial contribution to left ventricular filling (40±11 vs. 45±9%, P=0.02), a smaller left atrial dimension (54±20 vs. 47±18 ml, P=0.02) and a shortened E wave deceleration (235±64 vs. 196±42, P=0.002) by echocardiography. Further, D‐ribose also demonstrated a significant improvement of the patients quality of life (417±118 vs. 467±128, P≤0.01). In comparison, placebo did not result in any significant echocardiographic changes or in quality of life. This feasibility study in patients with coronary artery disease in CHF revealed the beneficial effects of D‐ribose by improving diastolic functional parameters and enhancing quality of life.

Echocardiographic Parameters for Predicting Maintenance of Sinus Rhythm After Internal Atrial Defibrillation

Chronic atrial fibrillation (AF), which is refractory to external electrical direct current shock and/or pharmacologic cardioversion, may be successfully cardioverted using internal atrial defibrillation. To avoid unnecessary procedures, it is important to be able to predict which patients will revert to AF. Thirty-eight patients with chronic AF underwent successful internal atrial defibrillation and were followed for 6 months after restoration of sinus rhythm. Left atrial (LA) diameter, left ventricular ejection fraction, maximum LA appendage area, and peak emptying velocities of the LA appendage were analyzed to determine which of these factors were associated with recurrence of AF. Forty-nine percent of patients had a recurrence of AF within 6 months following internal atrial defibrillation. The preprocedural ejection fraction (mean +/- SD 59 + 14% vs 57 + 13%, p = 0.63), LA diameter (4.2 +/- 0.6 cm vs 4.5 +/- 0.6 cm, p = 0.16), and LA appendage area (5.0 +/- 1.5 cm2 vs 5.8 +/- 1.5 cm2, p = 0.13) did not differ significantly between patients who maintained sinus rhythm and those who had recurrence of AF. Peak emptying velocities of the LA appendage before cardioversion were significantly lower in patients with recurrence of AF compared with patients who maintained sinus rhythm (0.26 +/- 0.1 m/s vs 0.49 +/- 0.17 m/s, p = 0.001). A peak emptying velocity <0.36 had a sensitivity of 82% and a specificity of 83% for predicting recurrence of AF.

Prevalence of left atrial chamber and appendage thrombi in patients with atrial flutter and its clinical significance.

OBJECTIVES The study was done to assess the prevalence of left atrial (LA) chamber and appendage thrombi in patients with atrial flutter (AFl) scheduled for electrophysiologic study (EPS), to evaluate the prevalence of thromboembolic complications after transesophageal echocardiographic (TEE)-guided restoration of sinus rhythm and to evaluate clinical risk factors for a thrombogenic milieu. BACKGROUND Recent studies showed controversial results on the prevalence of atrial thrombi and the risk of thromboembolism after restoring sinus rhythm in patients with AFl. METHODS Between 1995 and 1999, patients with AFl who were scheduled for EPS were included in the study. After transesophageal assessment of the left atrial appendage and exclusion of thrombi, an effective anticoagulation was initiated and patients underwent EPS within 24 h. RESULTS We performed 202 EPSs (radiofrequency catheter ablation, n = 122; overdrive stimulation, n = 64; electrical cardioversion, n = 16) in 139 consecutive patients with AFl. Fifteen patients with a thrombogenic milieu were identified. All of them had paroxysmal atrial fibrillation (AF). Transesophageal echocardiography revealed LA thrombi in two cases (1%). After EPS no thromboembolic complications were observed. Diabetes mellitus, arterial hypertension and a decreased left ventricular ejection fraction were found to be independent risk factors associated with a thrombogenic milieu. CONCLUSIONS The findings of a low prevalence of LA appendage thrombi (1%) in patients with AFl and a close correlation between a history of previous embolism and paroxysmal AF support the current guidelines that patients with pure AFl do not require anticoagulation therapy, whereas patients with AFl and paroxysmal AF should receive anticoagulation therapy. In addition, the presence of clinical risk factors should alert the physician to an increased likelihood for a thrombogenic milieu.

Right atrial appendage thrombosis in atrial fibrillation: its frequency and its clinical predictors

This study assesses the incidence of right atrial (RA) chamber and appendage thrombosis in patients with atrial fibrillation (AF) in relation to RA appendage morphology and function. Transthoracic and multiplane transesophageal echocardiography were performed in 102 patients with AF to assess the incidence of RA and left atrial (LA) thrombi and spontaneous echo contrast. Both right and left ventricular sizes, atrial chamber and appendage sizes and function were measured. Twenty-two patients in sinus rhythm served as the control group (SR). Complete visualization of the RA appendage was feasible in 90 patients with AF. Patients with AF had lower tricuspid annular excursion (p = 0.008) and larger RA chamber area (p = 0.0001) than patients in SR. In addition, RA appendage areas were larger (p <0.05) and RA ejection fraction and peak emptying velocities (both p <0.0001) were lower in patients with AF patients than in those in SR. Equivalent differences were found for the LA appendage. Six thrombi were found in the RA appendage and 11 thrombi in the LA appendage in AF patients. Spontaneous echo contrast was found in 57% and 66% in the right atrium and in the left atrium, respectively. AF patients with RA appendage thrombi had a larger RA area (p = 0.0001), and lower RA appendage ejection fraction and emptying velocities (both p = 0.0001) than patients without thrombi. Spontaneous echo contrast was detected in all patients with thrombi. Spontaneous echo contrast was the only independent predictor of RA (p = 0.03) and LA appendage thrombosis (p = 0.036). In conclusion, multiplane transesophageal echocardiography allows the assessment of RA appendage morphology and function. RA spontaneous echo contrast is the only independent predictor of RA appendage thrombosis.

Atrial fibrillation: relation between clinical risk factors and transoesophageal echocardiographic risk factors for thromboembolism

Objective: To correlate clinical risk factors for thromboembolism with transoesophageal echocardiography (TOE) markers of a thrombogenic milieu. Design: Clinical risk factors for thromboembolism and TOE markers of a thrombogenic milieu were assessed in consecutive patients with non-rheumatic atrial fibrillation. The following TOE parameters were assessed: presence of spontaneous echo contrast, thrombi, and left atrial appendage blood flow velocities. A history of hypertension, diabetes mellitus, or thromboembolic events, patient age > 65 years, and chronic heart failure were considered to be clinical risk factors for thromboembolism. Setting: Tertiary cardiac care centre. Patients: 301 consecutive patients with non-rheumatic atrial fibrillation scheduled for TOE. Results: 255 patients presented with clinical risk factors. 158 patients had reduced left atrial blood flow velocities, dense spontaneous echo contrast, or both. Logistic regression analysis showed that a reduced left ventricular ejection fraction and age > 65 years were the only independent predictors of a thrombogenic milieu (both p < 0.0001). The probability of having a thrombogenic milieu increased with the number of clinical risk factors present (p < 0.0001). 17.4% of the patients without clinical risk factors had a thrombogenic milieu whereas 41.2% of the patients presenting one or more clinical risk factors had none. Conclusion: There is a close relation between clinical risk factors and TOE markers of a thrombogenic milieu. In addition, TOE examination allows for the identification of patients with a thrombogenic milieu without clinical risk factors.

Transesophageal Echocardiographic Imaging of De Novo Thrombus Formation After Successful External Electrical Cardioversion of Atrial Fibrillation

One of the major risks of cardioversion of atrial ~brillation is the occurrence of thromboembolism [1]. Thromboembolism has been attributed to the dislodgement of preexisting left atrial thrombi, which are propelled into the systemic circulation with the restoration of sinus rhythm. However, recently it has been shown that thromboembolism may even occur in patients who did not have thrombi before cardioversion [2]. In order to explain this phenomenon, investigators performed transesophageal echocardiography during and after electrical cardioversion. They found that cardioversion itself may create a thrombogenic mileu in the left atrium, which potentially may cause the development of new thrombi in the left atrial chamber and appendage [3–5]. In this case study, we report on a patient who developed a new thrombus after external electrical cardioversion and discuss the clinical implications of our ~ndings.