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Biomedical subjects

C Palombo

Publications and source records attributed to C Palombo.

At least 73 records · Page 4Linked to original sources
PubMed1987

Long-term hypotensive treatment with nitrendipine in mild to moderate essential hypertension: preliminary results of a placebo-controlled study versus atenolol.

Nitrendipine is a dihydropyridine calcium antagonist suggested to be a new drug for first-line antihypertensive therapy, possibly active in once-daily administration. In the present study the acute and long-term hypotensive effects of nitrendipine have been evaluated in comparison with those of atenolol in a randomized, double-blind, clinical trial. Twenty-four patients have been studied, and the effects of treatment have been evaluated both at rest and during psychological and physiological stresses. Hemodynamic noninvasive parameters have also been obtained, at rest and during mental arithmetic tests, by a continuous-wave Doppler technique. Preliminary results about the first 13 consecutive patients are reported here. Nitrendipine induced a highly significant acute hypotensive effect (2 h after drug administration), whereas no effect was observed for atenolol except for heart rate. During chronic treatment (5 weeks), nitrendipine showed less hypotensive effect than atenolol when BP values 24 h after the last administration were analyzed, but significantly more effect when values obtained 2 h after drug administration were evaluated. These findings confirm that nitrendipine is effective in decreasing blood pressure, but the once-daily administration may not bring about the maximum effect in all patients. Interesting aspects of this drug, which make the clinical use of this compound safe, are represented by apparent lack in tolerance and rebound, and by the moderate increase in cardiac output associated with the treatment.

Adult↗
PubMed1987

Medium-term reproducibility of stress tests in borderline arterial hypertension.

Stress tests are commonly used for an evaluation of blood pressure reactivity, but few data exist in the literature about interindividual variability and intraindividual medium-term reproducibility of blood pressure responses to these tests in borderline hypertension. To this aim we have studied 20 borderline hypertensive patients (age range, 33-59, mean 45). Our data suggest that borderline hypertensive patients cannot be considered a homogeneous group with regard to blood pressure reactivity because they tend to have widely different blood pressure responses to various stress tests. For each test (except for orthostatic stimulation), a fairly good intraindividual reproducibility was found. Considering the poor correlations existing between blood pressure responses to tests for each patient, one test may not be sufficient to characterize blood pressure reactivity to stress in borderline hypertension.

Adult↗
PubMed1986

Acute hypotensive effect of calcium antagonists and endogenous digitalis-like immunoreactivity in human essential hypertension.

Evidence has been provided on the increased presence, in essential hypertension, of endogenous digitalis-like factor(s) [DLIS, digoxin-like immunoreactive substance(s)] able to cross-react with antidigoxin antibodies and to inhibit the membrane-bound sodium-potassium pump. An inhibition of the sodium pump could lead, in smooth muscle cells, to an increase of intracellular calcium ions and to an increase of total peripheral resistances. In this study the relation between plasma levels of DLIS and the acute hypotensive effect of a calcium antagonist (nifedipine) has been evaluated in a group of borderline to severe hypertensive patients and in a control group of normotensive subjects. The results obtained confirm that the hypotensive effect of nifedipine is related to pretreatment blood pressure and show, only in hypertensive patients, a significant relation of DLIS with both pretreatment blood pressure and blood pressure decrement induced by nifedipine. These findings are compatible with a possible role of DLIS in modulating cellular calcium handling.

Adult↗
PubMed1986

Echocardiography in the study of myocardial ischemia in man: the clinical model of Prinzmetal's angina.

Standard echocardiography was employed to study the clinical model of myocardial ischemia with ST-segment elevation, well known as Prinzmetal's angina. Ultrasonic monitoring was performed during the appearance of ST-segment elevation, from onset of pain, during an ergonovine maleate test, hemodynamic monitoring, radioisotopic studies and, occasionally, during routine examinations, when spontaneous episodes occurred. Reliability of findings was supported by two important conditions: each patient acted as his own control, since recording was carried out from basal state to basal state, throughout ischemia, or from ischemia to basal state; behaviour of ischemic walls was compared with that of non-ischemic ones. Echocardiographic findings in acute myocardial ischemia were similar both in spontaneous and in induced episodes and were mainly characterized by: decrease in contractility indices of the ischemic segment, such as wall motion and percent systolic thickening; increase in left ventricular end-systolic and end-diastolic diameter, with a decrease in percent fractional shortening; distorted shape of ventricular cavity, transiently deformed as in a "functional" aneurysm; a sharp demarcation between ischemic and non-ischemic adjacent segment, "step sign", was present only in severe cases. Taking ST-segment elevation as a reference the time sequence of events was studied, correlating mechanical, electric and clinical markers of ischemia. At least three different echocardiographic phases were identified in the evolution of ischemic attacks: Pre-electrocardiographic phase, when mechanical impairment is detected by ultrasounds in the absence of both ST-segment changes and pain; Electrocardiographic phase, when echocardiographic signs of ischemia co-exist with obvious electrocardiographic signs.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris, Variant↗
PubMed1985

Echocardiographic versus hemodynamic monitoring during attacks of variant angina pectoris.

Six attacks of variant angina (2 spontaneous, 4 induced by ergonovine) were studied in 6 patients by combined echocardiographic and hemodynamic monitoring. A decrease of percent systolic thickening of the ischemic wall, which occurred as early as the decrease in peak dP/dt of contraction, was detected before the onset of ST-segment elevation ("pre-electrocardiographic phase"). At this stage, no significant change in left ventricular (LV) end-diastolic pressure or end-diastolic diameter was observed. Subsequently, in the presence of clear-cut ST-segment elevation ("electrocardiographic phase"), percent systolic thickening (an index of regional function) reached its nadir, while dP/dt of contraction (an index of global function) was almost back to preischemic values. In this phase, a significant increase in LV end-diastolic diameter and end-diastolic pressure could be also detected. In the recovery phase, when the ST segment had returned to the isoelectric line ("post-electrocardiographic phase"), percent systolic thickening and dP/dt of contraction showed supernormal values, while LV end-diastolic pressure and end-diastolic diameter decreased below basal values. Thus, echocardiographic signs of impairment in LV mechanics are as early and sensitive as hemodynamic indexes during attacks of variant angina. Furthermore, information on morphologic characteristics and regional LV function, not available with hemodynamic monitoring, can be obtained by echocardiography.

Adult↗
PubMed1985

Transient myocardial ischemia with minimal electrocardiographic changes: an echocardiographic study in patients with Prinzmetal's angina.

Kn patients with Prinzmetal's angina, episodes of transient T wave abnormalities (T abn) are often documented in addition to the typical episodes of ST segment elevation (ST). As the interpretation of these minor ECG changes is still uncertain, we investigated if transient T abn are associated with reversible ventricular asynergies, similar to episodes with ST. For this purpose an ECG lead and a two-dimensional echocardiographic projection, which showed clear-cut changes during previous episodes of ST, were simultaneously monitored in five patients with Prinzmetal's angina for a total of 13 hours and 20 minutes. In all patients, the 30 episodes of ST recorded were all accompanied by reversible ventricular asynergies. Furthermore, in four of these patients, 14 episodes of T abn (peaking, flattening, or the appearance of a diphasic T wave) were recorded. All T abn were associated with reversible asynergies, as detected by three independent observers. The mechanical impairment occurred in the same ventricular wall both during ST and during T abn. During T abn the degree of mechanical impairment appeared less severe (hypokinesia in 12 and akinesia in two episodes) than during ST (hypokinesia in one, akinesia in 25, and dyskinesia in four episodes) (p less than 0.001). The duration of asynergies was less during T abn (107 +/- 76 seconds) than during ST (169 +/- 83 seconds) (p less than 0.05). Chest pain was reported in 5 of 14 episodes of T abn (36%) and in 20 of 30 (66%) episodes of ST (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Hypotensive effect of plasma exchange in immune complex nephritis.

The effect of plasma exchange (PE) on blood pressure (BP) in 20 hypertensive patients (9 with mixed cryoglobulinemia, 7 with systemic lupus erythematosus, and 4 with idiopathic glomerulonephritis) was evaluated retrospectively. In each PE 1.5-2.5 L of plasma was replaced with an equal volume of 4% albumin polysaline solution. The frequency of PE was three times per week for the first 2 weeks and twice per week subsequently. Sixteen patients were on hypotensive treatment at the onset of PE. Their systolic/diastolic BP was 171 +/- 4.7/102 +/- 3.0 mm Hg (mean +/- 1 SEM). After 4 weeks, BP decreased to 141 +/- 2.8/89 +/- 2.3 mm Hg (p less than 0.001), although in 10 patients antihypertensive drug therapy had been reduced or discontinued. The most marked decrease of BP occurred after the first week (152 +/- 5.3/92 +/- 2.9 mm Hg), and this decrement correlated remarkably well with pressure levels before PE despite the great heterogeneity of the individual patients (for diastolic BP, r = 0.87, p less than 0.001; for systolic BP, r = 0.60, p less than 0.01). A mild decrease of serum creatinine was observed during PE, but its time course was different from that of BP, and did not correlate with this parameter.

Adolescent↗
PubMed1985

Acute effect of plasma exchange on arterial blood pressure and plasma renin activity.

Blood pressure (BP) decreases significantly in patients with immune complex nephritis and hypertension in the course of therapeutic plasma exchange (TPE). To investigate possible underlying mechanisms of this effect, the variations of supine and upright BP and plasma renin activity (PRA) acutely induced by PE (performed by isovolumetric replacement of plasma with 4% albumin in saline solution) were analyzed in six patients. On the average, both supine and upright BP decreased after TPE; however, statistical significance was obtained only for upright systolic BP. Supine and upright PRA did not change significantly, although a clearly blunted response to posture was observed in three patients. The changes of BP induced by TPE were apparently not due to a functional depression of the renin-angiotensin system, since the more marked decrements in BP were observed in the patients with lower basal PRA.

Adolescent↗
PubMed1985

Electrocardiogram blood pressure and systolic time intervals long term monitoring in ambulant patients.

Ambulatory monitoring of the intra arterial blood pressure (IBP), through the Selyg-Oxford System, has been used so far primarily for studies on hypertension. Aim of our study is to explore the possibility of obtaining from IBP indications useful to extend its field of application. The study will investigate: the usefulness of the continuous monitoring of the systolic time intervals (STI), measured from IBP as ventricular performance indicators, the increasing of specificity of the ECG allowed by the simultaneous beat by beat estimate of the STI's, the possibility of achieving the same information from non invasive peripheral pressure transducers. In this paper we are presenting the results obtained from the combined analysis of the STI's, ECG and IBP in a first series of 13 patients, selected out of 50 on the basis of the highest number of episodes of IBP variations, to allow the evaluation of the algorithms performances in severe conditions.

Blood Pressure↗
PubMed1985

The intraarterial blood pressure monitoring in the evaluation of patients with dizziness and/or fainting.

Ambulatory blood pressure (BP) monitoring has been extensively utilized, so far, for studying BP profile and hypotensive treatment in arterial hypertension. In this paper, preliminary data will be reported from a clinical study on the possible contribution of the combined ECG and BP monitoring in clarifying mechanisms of dizziness in patients with multiple or complex cardiovascular problems. Results are shown of three patients with ischaemia, arrhythmias and/or episodes of hypotension, and of three patients with borderline hypertension and marked fluctuations of BP.

Arrhythmias, Cardiac↗
PubMed1985

Acute effect of captopril on single kidney glomerular filtration rate in arterial hypertension.

Recent studies have reported that captopril can acutely induce a marked decrease of glomerular filtration rate in kidneys affected by renal artery stenosis, an effect detectable by scintigraphic techniques. Experience which confirms and extends this observation, obtained in five patients with renovascular hypertension, is reported here. For comparison, eight essential hypertensives and six patients with non-vascular unilateral renal diseases were studied. In each patient the ratio of glomerular filtration rate between the two kidneys was estimated during two consecutive scintigraphic studies with the glomerular tracer 99mTc-DTPA: in all renovascular patients captopril induced a marked decrease of glomerular filtration rate on the affected side, whereas negligible changes were observed in all other subjects. These results confirm that captopril may almost completely suppress glomerular filtration in kidneys affected by unilateral renal artery stenosis, an effect which may not be apparent clinically because of compensation by the other kidney, but which is scintigraphically detectable. Renal scintigraphy after captopril is easy to perform and non-invasive. It therefore seems to be a promising tool for the screening of renovascular hypertension.

Captopril↗
PubMed1984

Transient changes in left ventricular mechanics during attacks of Prinzmetal's angina: an M-mode echocardiographic study.

M-mode echocardiograms were recorded in 12 patients with Prinzmetal's angina during 29 episodes of transient myocardial ischemia at rest (18 spontaneous and 11 ergonovine-induced). At peak ST segment elevation a regional mechanical impairment was observed in the interventricular septum during 23 episodes of angina and in the posterior wall during six episodes. In the 18 spontaneous episodes the left ventricular ischemic wall, when compared to the basal state, was found to have a significant reduction in motion (-76.3 +/- 9.1%) (mean +/- SEM), in diastolic thickness (-11.7 +/- 2.5%), and in percent systolic thickening (-88.0 +/- 5.6%). Increase in left ventricular end-diastolic diameter (+13.1 +/- 2.1%) and decrease in percent fractional shortening (-38.1 +/- 3.7%) were also observed. When ST segment was back to the isoelectric line, a transient overshoot in regional left ventricular function was observed. In induced episodes statistically significant changes could be detected by M-mode echocardiography even before appearance of ST segment elevation and anginal pain. No significant difference was found in type or degree of mechanical impairment between induced and spontaneous episodes. Therefore, in patients with Prinzmetal's angina: (1) M-mode echocardiography allows detection of mechanical changes due to transient myocardial ischemia; and (2) mechanical impairment occurs earlier than clinical (pain) and electrocardiographic (ST segment elevation) signs of transmural ischemia.

Adult↗
PubMed1984

Transient changes in left ventricular mechanics during attacks of Prinzmetal angina: a two-dimensional echocardiographic study.

Fifty-five ischemic attacks at rest with ST segment elevation were recorded by two-dimensional echocardiography (2DE) in 20 patients with Prinzmetal angina. Eighteen ischemic attacks were recorded starting from intravenous injection of ergonovine maleate while 37 spontaneous ischemic attacks were recorded from onset of either anginal pain or ECG changes or from the basal state. In each ischemic attack at least one of the following transient alterations was observed by 2DE during ST elevation: (1) Regional hypokinesia, akinesia, or dyskinesia; (2) "step sign," that is, a sharp demarcation between an akinetic or dyskinetic area and an adjacent normal or hypercontracting region; and (3) geometric changes in left ventricular shape, that is, globular appearance in diastole and hourglass silhouette in systole. Regional myocardial asynergy was detected earlier than onset of pain (which was not present in 21 [38%] ischemic episodes) or ST segment elevation on ECG, as documented in 40 ischemic episodes (16 induced and 24 spontaneous) in which echocardiographic monitoring was performed from basal state and carried on up to the appearance of ischemia. All described mechanical changes were fully reversible after pain subsided and ST segment was back to isoelectric, either spontaneously or with nitrates; furthermore, a contractile "rebound phenomenon" of the previously ischemic wall was observed in some episodes. In conclusion, these results outline a role for 2DE in detecting cardiac mechanical impairment due to transient myocardial ischemia with ST segment elevation in humans.

Adult↗
PubMed1981

[Diagnosis of transient acute myocardial ischemia in man by M-mode echocardiography (author's transl)].

Under basal conditions the echocardiographic findings in anginal patients (pts.) without previous myocardial infarction appears usually normal. Consequently, the usefulness of the ultrasounds evaluation in angina pectoris has been commonly considered poor and the utilization of this technique in coronary artery disease has been restricted to the detection of myocardial infarction in its acute phase or to its chronic mechanical alterations. The purpose of this study was to assess the possibility offered by M-mode echocardiography to detect changes caused by transient myocardial ischemia at rest in man, in view of the possible diagnostic application of this technique. The reported results were obtained from 25 ischemic attacks (13 spontaneous and 12 ergonovine induced) with ST segment elevation or pseudonormalization of a basally negative T wave at rest. The semiautomatic computerized analysis of echocardiograms continuously recorded during these attacks showed a reduction of motion and of systolic thickening, accompanied by a diastolic thinning of the wall involved by the ischemia. These changes occur very early: they appear few seconds before ECG changes and are accompanied by a reduction of contraction and relaxation dP/dt and precede the onset of chest pain; moreover, they are followed by an increase in left ventricular internal diameters. In conclusion M-mode echocardiography is a sensitive technique capable to detect transient myocardial ischemia in the course of spontaneous or induced angina with ST segment elevation or positivity of negative T wave. This approach could be helpful in the diagnostic evaluation of patients with atypical chest pain and/or aspecific ECG changes and it can be complementary to other non invasive techniques such dynamic ECG and nuclear cardiology techniques.

Acute Disease↗
PubMed1981

[Comparison between M-mode echocardiography and 201thallium myocardial scintigraphy for diagnosis of transient myocardial ischemia (author's transl)].

Purpose of this study was to evaluate the capability of M-mode echocardiography (M-mode) and of 201Thallium myocardial scintigraphy (201T1) to detect transient myocardial ischemia at rest in man. Fourteen male patients (pts) were studied by the two techniques under basal conditions and during episodes of angina at rest. Data were obtained in 2 pts in rapid succession during the same episode, in the remaining 12 pts in different episodes with electrocardiographic changes similar in site, type, entity and duration. Echocardiographic criteria of transient ischemia (reversible asynergies and transient reduction of systolic thickening) were present in 9/11 pts during episodes of ST segment elevation; the scintigraphic ones (reversible perfusion defects) in 10/11 pts. In 3 pts during episodes of ST segment depression M-mode was positive in 2, 201T1 in all three. The poor acoustic window in 2 pts and the involvement in one of left ventricular lateral wall not seen by M-mode on parasternal approach, may account for the 3 false negatives of M-mode. The single false negative of 201T1 can be related to the short duration (1') of the episode. A complete correspondence of site of ischemia, detected by ECG, M-mode and T1, was observed. In conclusion, M-mode appears a reliable technique for detecting transient ischemic episodes, being the main limits the acoustic window and the incapacity in exploring all ventricular walls and the main advantage the high temporal resolution, which permits to study continuously the full sequence of the ischemic event. On the other hand 201T1 does not allow detection of episodes of short duration. This two techniques, when combined in anginal patients, provide complementary information on perfusion and contraction respectively. The reliability of these techniques in the assessment of transient myocardial ischemia is the basis for their possible diagnostic use in pts with transient specific ECG changes or with typical anginal pain without ECG evidence of ischemia.

Adult↗
PubMed1978

The kinetics of plasma noradrenaline in normal and hypertensive subjects.

1. The kinetics of plasma noradrenaline have been determined in normal and essential hypertensive patients by intravenous injection of tritiated noradrenaline and serial mixed venous sampling. 2. The metabolic clearance rate of plasma noradrenaline in normal subjects was approximately 1 1 min-1 m-2, whereas in essential hypertensive patients it was significantly reduced to approximately 0.6 1 min-1 m-2. 3. Metabolic clearance rate was negatively correlated to mean arterial blood pressure and total peripheral resistances. 4. Particularly low values of metabolic clearance rate were found in two patients with congestive heart failure and one with phaeochromocytoma. 5. We propose that the access of plasma noradrenaline to the main removal mechanisms takes place in competition with the flow of unlabelled endogenous noradrenaline directly released by nerve endings. The slower removal of plasma noradrenaline in essential hypertension could then express a larger release of endogenous noradrenaline in this condition.

Adrenal Gland Neoplasms↗