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Biomedical subjects

S Romano

Publications and source records attributed to S Romano.

At least 145 records · Page 8Linked to original sources

[A case of pheochromocytoma with atypical clinical presentation].

A case of pheochromocytoma that had undergone coronary arteriography because it stimulated coronary heart disease is presented. The correct diagnosis was suspected while checking the signs and symptoms during an episode of pulmonary edema and was definitely proved by computed tomography and scintigraphy with I 131 metaiodobenzylguanidine. The authors stress the importance of these new non invasive procedures in the diagnosis of site and nature of this disease.

3-Iodobenzylguanidine↗

Circadian variability of blood pressure and heart rate in newborns and cardiovascular chronorisk.

At present, neonates are being given screening tests for relatively rare diseases, such as phenylketonuria. The time has come to give emphasis to assessing the risk for major handicapping diseases, such as coronary heart disease, stroke, and certain diseases of the kidney. Modern technology for blood pressure and heart rate monitoring and data analysis provides noninvasive means to determine when preventive measures are indicated.

Blood Pressure↗

Influence of age on polymorphonuclear leukocytes in vitro: phagocytic activity in healthy human subjects.

Polymorphonuclear leukocytes (PMNs) represent an important defensive mechanism against infectious agents. Some of their functions are impaired in old people, with a decreased effectiveness of nonspecific immunity. In vitro PMN phagocytic activity was studied with different techniques on 74 healthy subjects (20-82.5 years; 40 males, 34 females). Serum-mediated ingestion resulted to be impaired with age with a lower ratio of active PMNs and a lower activity of phagocytosing cells. The behavior of these parameters was age-related, without significant difference between males and females; the decline was found to be a continuous phenomenon with no threshold age. Serum-independent ingestion had very low values and was not impaired with aging. The present data can represent a further explanation for the finding of a higher incidence and mortality of bacterial diseases in elderly population.

Adult↗

[Intra-sinus echo: demonstration using direct intracavitary recording of the sinus potential].

The authors searched for intra-sinusal echos during electrophysiological investigation of 53 patients (41 men, 12 women, average age: 61 +/- 12 years). Cycles of sinus echos were recorded in 8 patients (15 per cent). The period during which sinus echos could be recorded was 125 ms (average 40.6 +/- 34 ms). Indirect assessment of sinus node function in patients with sinus echos was normal (corrected sinus node recovery time, estimated atrio-sino atrial conduction times using Narula's technique). A valid and reproducible direct recording of the sinus node potential was only possible in one patient. In this case the echo cycles were provoked by stimulation periods of between 440 and 320 ms (echo zone of 120 ms). All the echos obtained were preceded by a sinus node potential with a different duration and morphology to that observed during basal sinus cycles (respective sino-atrial conduction times 105 and 115 ms). In this patient we were also able to induce sinus echos after a single extrastimulus during the spontaneous rhythm. the echo zone was 130 ms and with a shorter coupling interval (310 ms) two successive sinus echos were recorded. The demonstration of intrasinusal echos by direct recording of the sinus node potential supports the experimental data of Allessie and Bonke on isolated right atrial tissues of the rabbit. Improvements in the technique of endocavitary direct recording of the sinus node potential in man should complete this data by showing the possibility of sinoatrial tachycardias due to reentry.

Action Potentials↗

Mexiletine action on the specialized tissues of the human heart.

Electrophysiological properties of mexiletine (3 mg/kg i.v.) were studied in fifteen patients with various degrees of abnormalities in the specialized conduction system. Sinus cycle length was decreased in all patients; sinus node recovery time was increased in all patients, but the increment was not statistically significant. Atrial and atrioventricular (AV) nodal refractoriness were not modified. The relative refractory period of the His-Purkinje system was reduced in patients with normal intraventricular conduction on the surface electrocardiogram; no changes were noted in five patients with intraventricular conduction delay. In two patients, in whom AV nodal refractory period curves showed antegrade dual AV nodal pathways, mexiletine increased refractoriness of the fast pathway. This report points out that the drug is effective against arrhythmias sustained by a reentry mechanism, not only in the ventricles, but also in the AV node.

Aged↗

[Sinus node electric activity in prolonged atrial pauses in subjects with the sick sinus syndrome].

Sinus node electrogram (SNE) was recorded in 15 patients with sick sinus syndrome (SSS) in which prolonged atrial pauses were observed. The aim of this study was clarify the physiopathological mechanisms underlying atrial pauses as well as to evaluate the sensitivity of sinoatrial conduction time (SACT) directly measured on SNE and of SACT estimated with the indirect Strauss method with respect to the detection of SSS. The following results were obtained: Sinus electrical activity was recorded during atrial pauses (greater than or equal to 2 basic sinus cycle length) in all the 9 patients in which the pauses spontaneously occurred and in the 2 patients in whom the pauses of 2860 and 3190 msec were induced by atrial pacing. In one of these latter two patients, moreover, a complete electrical desynchronization was observed. In the remaining 4 patients in whom, pauses (greater than or equal to 3 sec) were induced by carotid sinus massage of in 3 no sinus electrical activity was detected on SNE while in 1 advanced sinus node desynchronization was observed. Direct sinoatrial conduction time was abnormally prolonged in 6 patients with SSS and indirect sinoatrial conduction time in 9 patients.

Adult↗

Assessment of optimal dose of diuretic associated with fixed dose of beta-blocking: a new experimental model based on multiple sampling of blood pressure performed by self-measurements.

A new experimental model is presented for determining the optimum dose of 3 different doses (13 mg, 25 mg, 37 mg per day) of hydrochlorothiazide employed to enhance hypotensive effect of 200 mg/day of metoprolol in human hypertension. The model takes into account the circadian variability of blood pressure as sinusoidal function and wash-out effect as a linear trend so as to compensate for bias due to normal temporal variability.

Adrenergic beta-Antagonists↗

[The sinus node electrogram in the evaluation of atrial pauses].

The aim of this study was to establish the electrophysiological mechanism of atrial pauses, defined as a sudden lengthening of atrial cycle greater than or equal to 10% of its basal value. The sinus node electrogram (SNE) was recorded during electrophysiological study in 20 subjects. Satisfactory recordings of 64 pauses were obtained, 25 of which were spontaneous, 16 were induced by short periods of atrial pacing (AP) in normal subjects, whereas 23 atrial pauses were induced with the premature stimulation method. The basal sinus cycle and the one during the spontaneous pauses were measured from the upstroke slope on the SNE. The electrically induced pauses of the sinus cycle were measured from the artifact of the stimulus to the upstroke slope of the SNE of the first post-pacing beat. We have found that: 1-spontaneous atrial pauses correspond to a moderate slowing of the sinus cycle and to a depression of the sinoatrial conduction occasionally up to a second degree sinoatrial block. Only in subjects with sick sinus disease, the atrial pauses are induced by depression of the sinus automatism; 2-in normal subjects the AP results in a sinoatrial conduction delay; 3-the single extrastimulus regularly produces a moderate increase of the sinoatrial conduction time with variable but minimal effects on the sinus node automatism.

Cardiac Pacing, Artificial↗

Computerized M-mode echocardiography in the assessment of cardiovascular effects during intravenous administration of amiodarone.

Antianginal and antiarrhythmic long term therapy with amiodarone may be associated with side effects, therefore it should be used mainly in short term treatment of severe arrhythmias and acute coronary insufficiency. It is important to assess if any inotropic effect may be produced after intravenous administration of this drug in commonly accepted therapeutic doses (5 mg/kg body weight). To investigate this possibility we studied the effects of amiodarone on blood pressure (BP), on heart rate (HR) and on the maximal velocity of circumferential fiber shortening (Vcf Max). Simultaneous echocardiogram (UCG), electrocardiogram (lead DII) (ECG) and BP cuff measurement were performed on 12 subjects without cardiomegaly and clinical evidence of heart failure, immediately before a 30 second intravenous injection of amiodarone and every 30 seconds over a period of 6 minutes after drug administration. Amiodarone administration markedly raised HR within the first 30 seconds from the beginning of the injection and concomitantly decreased diastolic BP. No significant lowering of systolic BP was observed. Vcf Max (circ/sec) raised during the test concomitantly with HR increase, showing a significant relationship between left ventricular performance and HR. The same was also true during atrial pacing performed on one subject. No significant changes in any of the parameters studied were demonstrated after placebo (saline solution) administration to two presumable healthy subjects. Amiodarone does not seem to have any positive or negative intrinsic inotropic effect when administered intravenously at a dose of 5 mg/kg body weight.

Adolescent↗