Left ventricular filling pattern in {beta}-thalassaemia major -- a Doppler echocardiographic study

The pattern of left ventricular filling was assessed by Dopplerechocardiography in 38 adult ß-thalassaemia majorpatients; 28 with normal (age 25.2±5.3 years) and 10with abnormal (age 24.5±8.8 years) left ventricular systolicfunction. The findings were compared with those obtained from38 age and sex matched normal individuals. In patients with normal left ventricular systolic function,peak flow velocity in early diastole was higher than in thecontrols (94±16 vs 79±12 cm. s^–1 P <0.001).The peak flow velocity in late diastole was also greater (60±18vs 46±9cm. s^–1 P <0.001) but the ratio betweenthe early and late (atrial) peaks was approximately the samein both groups (1.74±0.72 vs 1.70±0.30 There wasno difference in deceleration time and rate between the twogroups (152±32 vs 151±21 ms and 504±93vs 508±115 cm. s^–2 respectively). None of the patientshad atrial predominant left ventricular inflow pattern. In patients with congestive heart failure the peak flow velocityin early diastole was greater than in the controls (96±10vs 79±2 cm. s^–1 P < 0.001) while in late diastoleit was smaller (39±6 vs 44±2 cm. s^–1 P <0.05).The ratio between the early and late peaks was greater in thepatients than in the controls (2.5±0.35 vs 1.8±0.08,P <0.001). The deceleration time and rate were not significantlydifferent in the two groups (153±33 vs 152±17msand 617±219 vs 550±56 cm. s^–2 respectively),until the end stage of congestive heart failure. Thus, leftventricular filling pattern in ß-thalassaemia majorpatients with normal left ventricular systolic function, issimilar to that seen in conditions of an increased preload.Patterns compatible with abnormally prolonged relaxation orrestriction do not appear.     

Accomplishments and Perspectives with Retrograde Nontransseptal Balloon Mitral Valvuloplasty

Retrograde nontransseptal balloon mitral valvuloplasty (RNBMV) is a transarterial technique of mitral valvuloplasty, developed with the aim to avoid complications associated with transseptal catheterization. Between April 1988 and December 1999, RNBMV has been attempted in 393 patients with symptomatic mitral stenosis (aged 44 ± 11 years, 322 women, mean echocardiographic score 7.7 ± 1.9) at the University of Athens, Greece. The procedure was completed in 392 cases. Technical success (gain in mitral valve area ≥ 50% with final mitral valve area ≥ 1.5 cm², and absence of postprocedural mitral regurgitation grade > 2+) was achieved in 344 (87.5%) patients. Unfavorable predictors for immediate outcome included the echocardiographic score (P < 0.001). male gender (P = 0.005), and preprocedural mitral regurgitation (P = 0.003). Complications included death (0.3%), severe mitral regurgitation (3.1%), and femoral artery injury (0.8%). No cases of cardiac peqoration or tamponade have occurred with RNBMV. Patients with a successful immediate outcome were followed clinically for 4.8 ± 2.8 years (maximum 12 years). Event-free (freedom from cardiac death, mitral valve replacement, redo valvuloplasty, and recurrence of NYHA Class > II) survival rates at 1, 2, 5, and 12 years post-RNBMV were 99.7 ± 0.3%, 96.1 ± 1.1%, 84.7 ± 2.2%. and 67.6 ± 4.8%, respectively. The echocardiographic score (P < 0.001) and the postprocedural mitral valve area (P < 0.001) were significant independent predictors of long-term outcome following RNBMV. Experience with RNBMV has fulfilled expectations regarding lowering of the risk of occurrence of specific cardiac complications encountered during mitral valvuloplasty, and reveals this approach as a safe and efficient alternative to the more commonly used antegrade technique.     

Role of Transesophageal Echocardiography in the Diagnosis of Infected Retained Pacing Lead

A 68-year-old woman had a tronsvenous pacemaker implanted 6 years ago. One year after the procedure the pulse generator was removed due to generator site infection. Efforts to remove the lead resulted in fracture of the tip, which was abandoned in the right cardiac cavities. After this the patient suffered intermittent episodes of fever and chills, which responded to antibiotic therapy. At her recent admission, transesophageal echocardiography revealed a large mass attached to the free end of the fractured lead suggestive of the existence of a vegetation on the pacing lead. The diagnosis was confirmed at surgery.     

Heart Rate Variability in Patients with Vasovagal Syndrome

The aim of this study was to assess the heart rate variability in patients with vasovagal syndrome (WS). Heart rate variability was expressed as: (1) the standard deviation (SD) of the mean RR interval; and (2) the SD as a percentage of the mean RR interval (%SD). Heart rate variability was measured in VVS patients and compared with control individuals. Eighteen patients (mean age 50 ± 14 years) with a history of recurrent syncope and positive tilt testing were included in the study. Fifteen asymptomatic individuals (mean age 53 ± 13 years) with no history of syncope and negative tilt testing were used as a control group. The SD and %SD (39 ± 38 and 5 ± 4 msec) in the WS group were statistically higher at the tenth minute of tilt testing than in the control group (20 ± 14 and 2.5 ±1.8 msec, P = 0.03 and P < 0.05, respectively). The mean RR interval (mean heart rate) was shorter after the 15th minute of tilt testing in the WS group than in the control group (RR-WS 687 ± 136 msec, RR-control 801 ± 131 msec, P < 0.05). It is concluded that heart rate variability, as expressed by the SD of the mean RR interval, and the SD as a percentage of the mean RR interval (%SD) are significantly higher in VVS patients than in control asymptomatic individuals.     

The effectiveness of {beta}-blockade and its influence on heart rate variability in vasovagal patients

The aim of this study was to assess the effectiveness of chronicmedical treatment with oral propranolol and its influence onheart rate variability in patients with vasovagal syndrome.A spectral frequency domain analysis was used for the estimationof heart rate variability characteristics. Thirty-six patients,mean age 49 ± 17 years, with a history of recurrent syncopeand positive tilt testing were involved in the study. All patientsreceived oral propranolol (five patients also had a dual chamberinhibited DDI pacemaker implanted) for a mean time 12 ±6 months. One patient complained of syncope during this follow-up.The tilt test repeated in 29 patients during follow-up was negativein 28. In 20 patients treatment was discontinued for 4 daysand a new tilt test was then performed. Eleven of these 20 patients(55%) had a positive test (P<0.001 compared with the groupin which treatment was continued). In the group of 11 patients in whom the tilt test became positiveagain after medical treatment had been withdrawn (mean age 43± 20 years) and in 11 asymptomatic controls (mean age52 ± 19 years), with no history of syncope and negativetilt testing, tile heart rate variability was assessed. Theincrease in the low frequency component from rest to the maximumvalue of heart rate variability during tilt testing was higherin the vasovagal group than in the controls (2.6 ± 1.2vs 1.5 ± 07 P = 0.02). The ratio between the increasesin the sympathetic and parasympathetic components was also higherin the vasovagal group (1.7 ± 0.7 vs 1.0 ± 0.3respectively P = 0.01). These differences during tilt testingwere eliminated after propranolol treatment. It is concluded that sympathetic activity is a predominant factorin the pathogenesis of vasovagal syndrome and that medical therapywith propranolol could be effective in vasovagal patients.     

Spontaneous Twisting of an Implanted Pacemaker Electrode in Three Cases

We present three cases of an unusual pacing lead aberration occurring at different times after implantation. In the first patient, the electrode was twisted close to the pacemaker, and dislodgment occurred on the 40th postoperative day. In the second case, there was only proximal twisting of the electrode. In the third case the electrode was twisted in two places: proximal to the pacemaker, and distal, within the right atrium. The complication was managed successfully by reimplanting the same electrode after stiffening the lead near the generator with a portion of the stylet.     

Acute effect of captopril administration on baroreflex sensitivity in patients with acute myocardial infarction

Depressed baroreflex sensitivity (BRS) after acute myocardialinfarction (AMI) is considered an indication of decreased vagaland/or increased sympathetic tone. To determine the effect ofangiotensin converting enzyme inhibitors (ACEI) on BRS afterAMI we studied 27 patients with a first Q wave AMI, no signsof heart failure and no history of arterial hypertension ordiabetes mellitus. An additional group of10 patients with thesame clinical characteristics served as controls. On the 5thday after the onset of AMI, three consecutive boluses of phenylephrinewere given intravenously and baseline BRS was taken as the meanslope of the linear regression lines of RR intervals over systolicblood pressure. QT interval was also measured and correctedaccording to Bazett's formula (QTc). Consequently, a singleoral dose of captopril 50 mg or placebo was given to treatmentor control group patients, respectively; BRS and QTc were reassessedlh later. One hour after captopril administration BRS increasedfrom 5.95±2.80 to 9.14±3.46ms.mmHg^–1 (P<0.0001);QTc increased from 414±46 to 425± 46 ms (P<0.0001),systolic blood pressure decreased from 125±19 to 115±15mmHg (P=0.0002), while heart rate did not change significantly.Baseline BRS was correlated only with age (r= 0.74, P<0.0001).In the control group, 1 h after placebo, no difference was observedin any variable compared to baseline. Captopril appears to improveBRS immediately in the early phase of AMI.