Spinal cord stimulation in patients with refractory anginal pain and normal coronary arteries.

BACKGROUND: Spinal cord stimulation (SCS) has been shown to be effective in patients with refractory angina and coronary artery disease. No previous study assessed the clinical effects of SCS in patients with refractory angina who present angiographically normal coronary arteries. METHODS: SCS was performed in 7 patients (4 men, 3 women, mean age 59.3 +/- 11 years) with refractory angina and normal coronary arteries. Clinical status was assessed 1 month after SCS device implantation and at a mean follow-up of 11 months (range 2-17 months) by: 1) an estimate of the number of anginal attacks and nitrate consumption in the 2 weeks prior to implantation and to follow-up visits; 2) a score of quality of life by a visual analogic scale; 3) a five-item questionnaire assessing effort angina and satisfaction with treatment; 4) treadmill exercise testing. RESULTS: At the last follow-up the number of anginal episodes (p < 0.001) and nitrate consumption (p < 0.004) were both reduced by SCS. Visual analogic scale score improved from 2.1 +/- 0.98 to 9.0 +/- 0.9 (p < 0.001) at 1 month and to 6.4 +/- 2.3 (p < 0.01) at the last follow-up. Questionnaire analysis showed that mild (p = 0.006) and moderate (p = 0.000) physical activity, as well as patient satisfaction with anginal status (p = 0.000) and with current treatment (p = 0.000) all improved by SCS. Finally, time to 1 mm ST segment depression, time to angina, and exercise duration were all prolonged by SCS. CONCLUSIONS: Our data point out that SCS may considerably improve anginal symptoms and exercise tolerance in a significant number of patients with refractory angina and normal coronary arteries and therefore it should be considered as a valuable treatment option in this group of patients.

Increased left ventricular mass in normotensive diabetic patients with autonomic neuropathy.

The possible relationship between diabetic autonomic neuropathy, circadian blood pressure changes, and echocardiographic parameters was investigated in 27 normotensive diabetic patients (10 with and 17 without autonomic neuropathy) who underwent 24 h noninvasive ambulatory blood pressure monitoring and M-mode echocardiographic recording. The two groups were comparable for age, sex, duration of diabetes, body mass index, and metabolic control. There were no significant differences in 24 h average and diurnal values of systolic, diastolic, or mean blood pressure. The percent changes from day to night of systolic, diastolic, and mean blood pressures were significantly lower in diabetics with neuropathy than in those without (P < .04 or less). Increased left ventricular mass index (LVMI) (135.4 +/- 10.2 v 102.9 +/- 6.3; P < .005), septal wall thickness, and posterior wall width were observed in neuropathic patients. Fractional shortening, peak velocity of early left ventricular filling (E), peak velocity of late ventricular filling (A), and their ratio (E/A) were similar in the two groups. The increased LVMI we observed may represent a possible link between diabetic autonomic neuropathy, nocturnal blood pressure levels, and higher cardiovascular mortality rate.

Calcium antagonists and hormone release. VIII. Effects of verapamil infusion on C-peptide to insulin molar ratio in normal subjects and obese subjects with normal glucose tolerance.

It is known that calcium-antagonist drugs can modify the insulin response to various secretagogues. In order to clarify whether calcium-antagonist effect was directed at the level of pancreatic insulin secretion or hepatic insulin extraction and further investigate the pathogenesis of hyperinsulinemia in obesity, an oral glucose tolerance test (OGTT) was performed in basal conditions and during a Verapamil infusion (VE, 5 mg/h x 3.5 h) in 12 normal subjects and 14 obese patients with normal glucose tolerance.(ABSTRACT TRUNCATED AT 250 WORDS)

Spinal cord stimulation and cerebral haemodynamics.

An increase of regional cerebral blood flow (rCBF) has been shown to occur in man during spinal cord stimulation (SCS) by Hosobuchi (1986) and by Meglio et al. (1988) using the 133-Xenon wash-out technique. In this paper we report the effects of SCS on CBF as measured by two different techniques: 8 patients were studied with the 133-Xe method and 28 with the transcranial doppler sonography (TCD), in two cases both studies were performed. The aim of our study was to: 1-verify the effect of SCS on CBF, 2-compare observations made by two different methods, and 3-evaluate a possible correlation between the stimulated spinal segmental level and the modification of CBF. The results of our study confirm that SCS interacts with the mechanisms of regulation of CBF. The stimulation of different spinal cord levels in the same patient can produce different effects and such effects are reproducible. An increase of CBF is more likely to occur with the stimulation of the cervical spinal cord. In patients studied by both methods the sign of CBF changes induced by SCS was the same. Finally, in two patients the effect of SCS on CO2 autoregulation was studied with TCD. The results of such a study, although preliminary, suggest that CO2 and SCS have a competitive effect upon the mechanisms of regulation of CBF.

Evaluation of metabolic status in amiodarone-induced thyroid disorders: plasma coenzyme Q10 determination.

In previous works we have demonstrated that Coenzyme Q10 (CoQ10) levels have a significant inverse correlation with thyroid hormone concentration in patients with spontaneous hyper- or hypothyroidism. In order to verify whether this correlation is maintained in patients on long-term amiodarone therapy, in whom thyroid metabolism is altered by the iodine contained in the drug, we have studied 30 patients with thyroid dysfunction induced by chronic amiodarone treatment. We have distinguished four groups of patients: group A (n = 8): patients with true hyperthyroidism induced by drug administration; group B (n = 11): patients with mild hyperthyroid symptoms, but isolated thyroxine increase or dissociation between different indexes of thyroid function; group C (n = 5): patients with normal thyroid hormone levels, but increased TSH levels; group D (n = 6): patients who appeared really clinically euthyroid, with normal thyroid hormone levels and normal TSH response to TRH. In group A patients, plasma CoQ10 levels averaged 0.49 +/- 0.03 micrograms/ml, significantly lower than those in normal subjects and similar to those observed in spontaneous hyperthyroid patients. In group B patients, CoQ10 levels were in the normal range (0.88 +/- 0.10 microgram/ml). In group C patients, CoQ10 levels were lower than those in normal subjects and similar to those of group A patients (0.49 +/- 0.04 microgram/ml); they differed, in regards to CoQ10 values, in comparison with spontaneous primary hypothyroid patients, who had very high levels of plasma CoQ10. Finally, in group D patients, CoQ10 levels were in the normal range (0.77 +/- 0.04 microgram/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Electrophysiologic effects of somatostatin in man.

Experimental and clinical studies suggest that somatostatin, a regulatory peptide widely distributed in human tissues may have electrophysiologic effects. We studied a group of 14 patients who underwent a complete electrophysiologic study for different rhythm disturbances. Somatostatin significantly increased the spontaneous cycle length, the atrial and atrioventricular nodal effective refractory periods, and the Wenckebach cycle length. The AH and HV intervals during sinus rhythm remained unchanged. The effectiveness of somatostatin to interrupt paroxysmal supraventricular tachycardias was assessed in 18 patients. Termination was obtained in 15 (82.5%). Our results show that somatostatin has a significant electrophysiologic effect on the human heart, and confirm its clinical effectiveness in some arrhythmias.

Spinal cord stimulation affects the central mechanisms of regulation of heart rate.

The effect of spinal cord stimulation (SCS) on heart rate (HR) was studied in 25 patients without cardiological symptoms, who were undergoing SCS for various reasons. HR at rest significantly decreased during SCS. Physiological and pharmacological maneuvers of sympathetic and parasympathetic activation or blockade before and during SCS indicate that SCS interferes with the central mechanisms of regulation of HR mainly by inducing a functional sympathectomy, and that such an effect is mediated by an action on spinal cord ascending fibers.

Evaluation of pituitary-thyroid axis response to acute myocardial infarction.

We have studied with seriated controls for a period of 9 days 18 patients admitted to our hospital for acute myocardial infarction (AMI). Slight, but non significant variations in thyroidal hormone pattern were observed: slight decrease of T3 and T4 levels, increase of reverse T3 on day 3, low free T4 levels, slight increase of TSH levels until the 3rd day. However, hormonal pattern was clearly different in patients who presented a clinical improvement (group 1a) and in patients who died for AMI (group 1b). In fact, a significant TSH increase was recorded in patients of group 1a; on the contrary, a significant decrease of TSH, T4 and free T4 concentrations was observed for subjects of group 1b, suggesting an inadequate response of pituitary-thyroid axis. In conclusion, the evaluation of thyroid hormones and thyrotropin levels can be of clinical usefulness in the management of patients with AMI. The decrease of plasma T4 and free T4 concentrations, accompanied with low TSH levels, can be associated with unfavorable course of the disease and therefore can be considered a bad prognostic sign.

[Comparative echocardiographic and vectorcardiographic study of 17 patients with Duchenne muscular dystrophy (author's transl)]. / Studio comparativo ecocardiografico e vettorcardiografico di 17 pazienti con distrofia muscolare progressiva tipo Duchenne.

Cardiac impairment in Duchenne muscular dystrophy (DMD) is well known since many years. Degeneration of myocardial fibers and progressive scarring of the left ventricle, especially in the postero-basal and lateral portions, represent the habitual cardiac pathologic features of post-mortem investigations. Nevertheless many questions about etiopathogenesis and pathophysiology of "DMD cardiomyopathy" are still debated. Clinical, vectorcardiographic (VCG) and echocardiographic (ECO) data of 17 patients suffering from DMD are here reported. Patients were subdivided in two groups according to age: A) subjects from 4 to 10 yrs. (mean 0.22 +/- 1.82 yrs.), 10 cases; B) subjects from 11 to 20 yrs. (mean 15.2 +/- 2.8 yrs.), 7 cases. Both patients groups were compared with age-matched normal controls (group A1 and B1). Our results show: 1) cardiac clinical symptoms and signs, even if is present in infancy, become more evident in adult age; 2) echocardiogram allows an early diagnosis and accurate follow-up of such cardiac pathology. Group A patients, in comparison with his own control group, exhibited a significant impairment of the left ventricular function indexes (PWE, IVSE, SV, Vcf, EF%, delta S%). Moreover the older group of patients (group B), besides the alteration of the above mentioned indexes, exhibited a significant decrease of the PWT and an impairment of DEVM. This, in agreement with other Authors, gives evidence to the progressive deteriorating of cardiac function in DMD. 3) A significant correlation between ECO and VCG data is lacking. Nevertheless VCG also displays a clear tendency to get worse with age. Vectorcardiographic features well agree with the post-mortem findings of a progressive but scattered myocardial fibrosis with elective localization in postero-basal and lateral (free wall) portions of left ventricle. 4) For the most part, in our patients, cardiological instrumental findings (ECO and VCG) are well in agreement with clinical data and natural history of "DMD cardiomyopathy". The afore said methods of investigation appear very useful in the diagnostic and therapeutic management of such patients.

[Comparison between vectocardiogram and echocardiogram in the diagnosis of left atrial enlargement (author's transl)]. / Confronto tra vettorcardiogramma ed ecocardiogramma nell'ingrandimento atriale sinistro.

The purpose of this study was to evaluate the influence of atrial enlargement on P wave abnormalities in "primary" (mitral stenosis) and "secondary" (left ventricular involvement) forms of left atrial overload. Echocardiograms and Frank Vectorcardiograms were obtained from 42 subjects, including 12 patients with mitral stenosis (group I A), 4 with mitral insufficiency (group I B), and 26 with left ventricular disease. Good correlations were founded between left atrial dimension and the following vectorcardiographic criteria: magnitude of the positive P vector in lead Z, sum of the positive P wave in leads X and Z, P positive duration/PR segment ratio in lead Z. No specific difference has been found in the vectorcardiographic abnormalities of the "primary" and "secondary" left atrial enlargement. Separate analysis revealed that P wave duration or amplitude changes can be proposed in group I A as specific and sensible criteria of left atrial enlargement. In contrast, the same criteria are highly unspecific when applied to the patients with left ventricular disease, because they can reflect the influence of other variables (left atrial pressure, intra-atrial conduction defects). Comparison of our results with those of other studies of P wave analysis did not demonstrate the superiority of the vectorcardiogram over the conventional electrocardiogram in the diagnosis of left atrial enlargement.