Sergio Ferraro

Left Ventricular Systolic and Diastolic Function in Severe Obesity: A Radionuclide Study

To verify the impact of sever obesity (defined as body mass index > 31 kg/m2) on left ventricular (LV) function, 32 asymptomatic obese but otherwise healthy subjects (16 men; age 38 +/- 11 years) voluntarily underwent first-pass and equilibrium 99mTc radionuclide angiography at rest and, in 22 of them, during bicycle supine exercise. Data were compared to those obtained from 10 normal volunteers (age 48 +/- 13; p < 0.05, vs. obeses). End-diastolic and stroke volumes did not differ between the two groups, whereas end-systolic volume was significantly higher in obese subjects (67 +/- 20 vs. 49 +/- 20 ml; p < 0.05), and, as a consequence, LV ejection fraction at rest was decreased in obese subjects (59 +/- 7%) compared to normals (65 +/- 6%; p < 0.05). Due to the higher heart rate in obese subjects (81 +/- 13 vs. 69 +/- 10 pbm, respectively; p < 0.05) cardiac output was significantly greater compared to normals (7.1 +/- 0.8 vs. 6.2 +/- 0.2 liters/min, respectively; p < 0.01). During exercise, ejection fraction normally increased in normals (70 +/- 7%; p < 0.001, vs. baseline) but not in obese subjects (60 +/- 9%; p = nonsignificant vs. baseline). In addition, systolic blood pressure/end-systolic volume ratio was significantly decreased in obese subjects (23 +/- 1.3) compared to normals (2.8 +/- 1.6; p < 0.05). Peak filling rate, normalized to end-diastolic counts per second, was significantly lower in obese subjects (2.2 +/- 1.3) compared to normals (2.8 +/- 1.6; P < 0.05). This difference was also true when peak filling rate was computed in stroke counts per second (3.8 +/- 0.8 in obeses vs. 4.4 +/- 0.4 in normals; p < 0.05). Repeat analysis in a subgroup of 10 young obese subjects (age < or = 30 years) confirmed decreased ejection fraction at rest (60 +/- 4%; p < 0.05) and peak filling rate (2.4 +/- 0.4 end-diastolic counts/s; p < 0.05), as well as the lack of ejection fraction increase during exercise (59 +/- 9%). Thus, these data indicate a subclinical impairement of LV systolic and diastolic function at rest and during exercise in asymptomatic severely obese but otherwise healthy subjects.

Comparison of left ventricular function in insulin- and non-insulin-dependent diabetes mellitus

Diabetes mellitus has been reported to have controversial effects on left ventricular (LV) function in patients with no evidence of coronary artery disease. In this study, LV function at rest was evaluated in 2 groups of diabetic patients, with insulin-dependent (IDD; n = 16) and non-insulin-dependent (NIDD; n = 23) diabetes mellitus, with no evidence of coronary artery disease. All patients underwent an electrocardiographic stress test, and first-pass and equilibrium radionuclide angiography at rest and during supine exercise. Data in each group of diabetic patients were compared with those obtained from age- and sex-matched normal subjects. In both groups of diabetic patients plasma catecholamine levels were significantly greater than in control subjects. Ejection fraction at rest and during exercise did not differ between each group of diabetic patients and their respective control group. In patients with IDD, peak ejection rate (4 +/- 1 end-diastolic count/s) was significantly greater than in control subjects (2.6 +/- 0.1 end-diastolic count/s; p < 0.001); similarly, peak filling rate (4.3 +/- 1.0 end-diastolic count/s) was significantly greater than in controls (3.0 +/- 0.2 end-diastolic count/s; p < 0.001). Cardiac output and systemic vascular resistances did not differ between patients with IDD and control subjects. In contrast, patients with NIDD had significantly reduced cardiac output compared with that of control subjects (5.7 +/- 0.2 vs 5.9 +/- 0.2 liter/min; p < 0.01), and increased systemic vascular resistances (1,422 +/- 137 vs 1,314 +/- 68 dynes.s.cm-5; p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy of Ticlopidine in the Prevention of Thromboembolic Events in Patients with VVI Pacemakers

This study was designed to evaluate whether long‐term treatment with ticlopidine reduces the incidence of thromboembolie episodes in patients with a VVI pacemaker. One hundred eJeven patients with a VVI pacemaker were randomly assigned to two groups: group A (52 patients) was treated with ticlopidine at the dose of 250 mg a day; and group B (59 patients) was not treated and served as a control group. The primary analysis of efficacy of ticlopidine was based on the occurrence of thromboemboJic episodes and of cardiovascular and cerebrovascular deaths. The mean follow‐up period was 66 months. In group A, there was a significant reduction in the incidence of thromboembolic episodes (P < 0.05) with a smaller incidence of total cardiovascular and cerebrovascular deaths (8 in group A and 18 in group B; P = 0.05) as compared with group B. Twelve percent of patients had moderate side effects with 1 dropout (epistaxis). Our data confirm the high incidence of thromboembolic events in patients with a VVI pacemaker and demonstrate the efficacy of ticlopidine in preventing them.

Pacemaker Malfunction Due to Subcutaneous Emphysema — A Case Report

The authors describe a case of pacemaker malfunction due to a critical in crease of impedance resulting from air entrapment in the pacemaker pocket.

Fourier Analysis in Patients with Different Pacing Modes

The purpose of this study was to evaluate the usefulness of phase analysis in detecting the altered activation sequence induced by different pacing modes. Radionulide ventriculography and planar gated blood pool scintigraphy were performed at rest in 56 patients with different pacemakers. This method permitted us to localize the pacemaker impulse site in the right ventricie and its diffusion in the heart. In patients with VVI pacemaker, this technique showed an evident asynchronism of contraction and relaxation of each ventricle and the standard deviation of phase angle (σ), calculated by computer, is greater during pacing than sinus rhythm for left (LV) and right (RV) ventricles (LV σ: 17°± 4 vs 11°± 3, < 0.001; RV σ: 31°± 7 vs 14°± 4, P < 0.001). In the patients with VVI rate responsive pacemakers, the LV σ changed from 18.5 ± 3 under pacing to 11°± 3 in sinus rhythm, P < 0.001, while the RV σ changed from 30°± 8 to 14°± 4, P < 0.001. Instead in the patients with DDD pacemakers, the LV σ changed from 15.5°± 2 under pacing to 11°± 3 in sinus rhythm, P < 0.05, while the RV cr changed from 29.1°± 6 to 14°± 4, P < 0.001. Besides in patients with VDD pacemakers, the LV σ changed from 14.9°± 3 during pacing to 11°± 3 in sinus rhythm, P < 0.01, and from 27.5°± 5 to 14°± 4 for the right ventricle, P < 0.01. So the technique of Fourier analysis permits us to examine the effects of a temporal inhomogeneity induced by different pacing modes, and it can be utilized to assess the optimal atrioventricular delay in DDD paced patients.

Follow-Up of a Respiratory Rate Modulated Pacemaker

The efficacy of 27 respiration sensitive rate modulated pacemakers (Biorate RDP‐3, Biotec) implanted in the left pectoral area was evaluated every 3 months during a mean follow‐up period of 29 months (range 10‐50 months]. Rate modulation function was unchanged other than for three patients in whom the auxiliary leads became displaced. Two implants lost ventricular sensing in this nonprogrammable model. In all but the three patients, Holter monitoring demonstrated pacing rate variation corresponding to daily activity. Stress test duration increased from 8.2 ± 1.5 minutes (in fixed rate WI rate) to 12.83 ± 2.0 minutes (in the VVIR mode) (P < 0.05). Right arm movement increased the pacing rate by 5 ± 3 beats/min (NS), while the left arm movement increase was 30 ± 5 beats/min (P < 0.05). Mental, arithmetic, and nifedipine tests did not change the rate modulated pacing rate. The system responded to a change in respiratory rate by an increase in stimulation rate. A satisfactory response in sensitivity and velocity was present only with medium‐high workloads. Interference with rate modulation occurred with movement of the arm ipsillateral to the implanted pulse generator.

Efficacy of sildenafil in HIV-related pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is one of the long-term complications of HIV infection. The incidence of HIV-PAH is estimated at 0.5% of HIV-infected individuals. The mechanism by which infection leads to full-blown PAH is unknown. We describe a 44-year-old female patient with HIV infection diagnosed in 2004. Pulmonary hypertension was diagnosed in 2006. Seven months after the first cardiovascular clinical signs had started, the patient was referred to hospital because she was in New York Heart Association functional class IV. She commenced treatment with sildenafil. After increasing the sildenafil dose to ensure therapeutic drug levels over 24 h, the PAH and physical performance of the patient improved significantly. Our experience confirms long-term benefits of sildenafil monotherapy in PAH-HIV adult patients with improvements in symptoms and echocardiographic findings.

Pacemaker Malfunction Due to Subcutaneous Emphysema A Case Report

The authors describe a case of pacemaker malfunction due to a critical increase of impedance resulting from air entrapment in the pacemaker pocket.

Diagnosis of Coronary Artery Disease with Tc 99m-Methoxy Isobutil Isonitrile and Transesophageal Pacing

Recently the use of a new radioactive agent with physical and biological properties more favorable than those of thallium 201, methoxy-isobutyl-isoni tryl (MIBI) labeled with technetium 99m (Tc 99m), has permitted simultaneous performance of perfusion and function studies in ischemic cardiopathy. Transe sophageal atrial pacing (TAP) technique has evolved as an alternative provoca tive test of ischemia. The authors compared the capability of Tc 99m-MIBI myocardial scintigraphy, combined with TAP, with that of Tc 99m-MIBI, com bined with maximal stress test, in the diagnosis of ischemic cardiopathy. They studied 11 patients with a clinical history of angina pectoris. Myocardial scinti graphy was performed at rest, after stress test, and after TAR Finally, all the patients underwent coronary angiography. The analysis of myocardial perfu sion images on both Tc 99m-MIBI associated with TAP and with stress demon strated, in 165 myocardial segments examined: 143 normal, 20 reversible de fects, 2 irreversible defects. The concordance of localization between corono graphic data and scintigraphic reversible and irreversible defects was 85%. In conclusion TAP proves to be a valid and sensitive provocative test of ischemia when combined with myocardial scintigraphy and with Tc 99m-MIBI.