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Biomedical subjects

G Longobardi

Publications and source records attributed to G Longobardi.

At least 37 records · Page 2Linked to original sources

Left ventricular diastolic filling in elderly hypertensive patients.

OBJECTIVE: To evaluate the effects of mild to moderate hypertension and of LVH on diastolic filling and other Doppler indices in the elderly. DESIGN: Survey with a control group. SUBJECTS: Seventy-one hypertensives (34 men, 37 women) referred for echocardiograms and 32 age- and sex-matched normotensive volunteers. Thirty-six of the hypertensives had LVH; 34 did not. SETTING: Echocardiographic laboratory. MEASUREMENTS: M-mode, two-dimensional, and pulsed Doppler echocardiograms. A wide variety of Doppler-derived indices of diastolic function were assessed. RESULTS: All Doppler derived indices of left ventricular diastolic filling (peak E, peak A, their ratio, EF slope, time-velocity integrals, atrial filling fraction, and isovolumic relaxation time) were similar among the three groups. CONCLUSION: Elderly mild to moderate hypertensives with or without LVH have LV diastolic filling that is normal for age. The identification of pathological diastolic dysfunction requires comparison to age-matched controls, since aging, a major factor influencing diastolic filling, can mask the effect of hypertension.

Age Factors↗

Effect of beta-adrenoceptor blockade on dipyridamole-induced myocardial asynergies in coronary artery disease.

Twenty-one patients with angiographic evidence of significant coronary artery disease, and positive dipyridamole echocardiographic test results at basal condition and after 7 days of placebo treatment were prospectively studied to see whether beta blockade modifies the effects of dipyridamole echocardiographic testing on regional myocardial contractility. Patients were randomized to propranolol (120 mg/day) or placebo treatment in 3 divided doses for 7 days, after which each patient crossed over to the alternate regimen. Dipyridamole-echocardiographic testing was repeated at the end of each treatment. Propranolol abolished new mechanical signs of transient dipyridamole-induced ischemia (new wall motion abnormalities or an increase in degree of basal asynergies, or both) in 13 of 21 patients. The remaining 8 patients had positive results on dipyridamole echocardiographic testing after the propranolol treatment period. At basal conditions both heart rate and rate-pressure product were significantly reduced with propranolol; there was also a significant decrease in these parameters at peak dipyridamole infusion. At peak dipyridamole infusion heart rate and rate-pressure product were significantly lower in patients with negative than in those with positive echocardiographic test results after propranolol. Our data show that administration of beta blockade significantly reduces the development of transient dipyridamole-induced myocardial asynergies, the earliest markers of acute myocardial ischemia, detected with 2-dimensional echocardiography.

Adrenergic beta-Antagonists↗

Parental smoking and asthma in childhood.

The effect of parental smoking on childhood asthma was investigated in which data from 302 asthmatic and 433 healthy children aged 1 to 12 years, were studied. All asthmatic patients received prick tests for common allergens. A significantly higher number of heavy parental smokers was found in asthmatic children under 6 years of age with negative prick tests (P = 0.02). A stepwise logistic regression was performed in order to verify interactions between parental smoking and other variables. It is concluded that parental smoking is an important risk factor for "prick test negative" asthmatic children aged 6 years or less.

Asthma↗

Regional left ventricular mechanical function during isometric exercise in patients with coronary artery disease: correlation with regional coronary blood flow changes.

The effects of isometric exercise on regional left ventricular mechanical function and regional coronary blood flow were evaluated in 17 patients with significant proximal stenosis of the left anterior descending coronary artery and 10 patients with normal coronary arteriograms. All patients had normal myocardial contractility in the basal condition. All performed isometric handgrip exercise at 50% of the maximal voluntary contraction for 3 min during two-dimensional echocardiographic monitoring and hemodynamic evaluation of great cardiac vein flow by thermodilution technique. During isometric exercise, 7 of the 17 patients with left anterior descending coronary stenosis developed asynergy in the anterior territory (anterior or septal segment, or both) (group I); the remaining 10 showed normal myocardial contraction during the test (group II). The 10 normal subjects manifested no regional asynergy during the test (control group). The increase in great cardiac vein flow at peak isometric exercise was significantly smaller (p less than 0.01) in group I (+15 +/- 8%) than that in group II (+98 +/- 48%) and the control group (+64 +/- 22%). Anterior coronary vascular resistance decreased in group II (-32 +/- 13%) and in the control group (-25 +/- 8%) but increased in group I (+6 +/- 8%, p less than 0.01 versus group II and control group). These data demonstrate that handgrip-induced myocardial asynergy is associated, in our study patients, with an abnormal response of the regional coronary circulation. The increase in coronary vascular resistance in group I patients with asynergy demonstrates that functional mechanisms play a dominant role in left ventricular mechanical dysfunction induced by isometric exercise.

Aged↗

[Action of magnesium salts on the toxic effects of calcium overload in the isolated and perfused rat heart].

The toxic effect of calcium overload and the action of magnesium sulfate (4 mM) and magnesium chloride (4 mM) on heart rate, coronary flow rate, left ventricular systolic pressure, dp/dt max and voltage epicardial electrogram were studied in the isolated and perfused rat heart. Increasing calcium load by increasing [Ca]o from 1 to 6 mM we observed a progressive increase in heart rate coronary flow rate, left ventricular systolic pressure, dp/dt max and a decrease in voltage epicardial electrogram. During the exposure to [Ca]o 8 mM the toxic manifestations of calcium overload developed and we observed a reduction in heart rate, coronary flow rate, left ventricular systolic pressure, dp/dt max and an increase in voltage epicardial electrogram. Magnesium sulfate and magnesium chloride had similar effect: in fact, in both procedures we observed a decrease in heart rate, left ventricular systolic pressure, dp/dt max, voltage epicardial electrogram and an increase in coronary flow rate at [Ca]o 2 mM. When magnesium salts were administered at the same time as the heart was exposed to [Ca]o 8 mM, we observed a reduction in the toxic effect of calcium overload. When magnesium salts were administered after the appearance of the calcium overload, they did not revert the toxic effect of calcium overload but prevented the insurgence of cardiac standstill. Thus, in the isolated perfused rat heart, the toxic manifestations of calcium overload develop at [Ca]o 8 mM and magnesium salts are able to reduce the toxic effects of calcium overload and the appearance of cardiac standstill according to their calcium-antagonism mechanism.

Animals↗

Role of increased cholinergic activity in reperfusion induced ventricular arrhythmias.

The effect of increased cholinergic activity on reperfusion induced ventricular arrhythmias was studied in alpha chloralose anaesthetised dogs by administering neostigmine during a 25 min occlusion of the anterior left descending coronary artery. The dogs were divided into five groups, each of 10 animals: the control group received only saline solution; group 1 neostigmine 0.03 mg.kg-1 iv at 20 min of coronary occlusion (that is, 5 min before reperfusion); group 2 atropine 0.4 mg.kg-1 iv at 10 min of coronary occlusion and neostigmine 0.03 mg.kg-1 iv at 20 min; and group 3 neostigmine 0.03 mg.kg-1 iv at 20 min of coronary occlusion and at the same time underwent atrial pacing at the same rate as that of the sinus node just before neostigmine administration. In group 4 heart rate was slowed (junctional rhythm) by destroying the sinus node at 20 min of coronary occlusion. The results obtained showed that ventricular tachycardia and fibrillation, which occur at the beginning of reperfusion, were significantly less frequent in group 1 (p less than 0.001) and in group 4 (p less than 0.001). The protective action of neostigmine was abolished by previous administration of atropine (group 2) and modified by preventing the decrease in the heart rate by atrial pacing (group 3). In group 3 ventricular tachycardia was more frequent but the incidence of ventricular fibrillation was reduced significantly compared with the control and atropine groups. Thus cholinergic activity has a protective role in reperfusion arrhythmias by decreasing the heart rate before release of the coronary occlusion and therefore reduces the incidence of ventricular fibrillation.

Animals↗

Use of the epinephrine test in diagnosis of coronary artery disease.

Two-dimensional echocardiographic (2-D echo) and electrocardiographic (ECG) monitoring was performed in 53 patients with anginal chest pain during infusion of physiologic doses of epinephrine. Technically adequate 2-D echo studies were recorded in 45 patients. Of these 45 patients, 35 had significant coronary artery disease. Twenty-two patients showed ECG changes during the test (ECG sensitivity 63%), 13 of whom also showed wall motion abnormalities (2-D echo sensitivity 48.5%). Combined ECG and 2-D echo criteria of a positive test yielded a sensitivity of 74%. None of the 10 patients without coronary artery disease had electrical or mechanical abnormalities during the test (specificity 100%). Thus, the epinephrine test during simultaneous 2-D echo and ECG monitoring is a valid alternative to echocardiographic exercise stress testing. Furthermore, the adequate images obtained during the infusion allow better investigation of relation between wall motion abnormalities and ECG changes during myocardial ischemia.

Adult↗

Two-dimensional echocardiographic evaluation of ventricular asynergy induced by dipyridamole: correlation with thallium scanning.

Myocardial asynergies detected by two-dimensional echocardiography during intravenous administration of Dipyridamole (0.75 mg/kg) were evaluated in 54 patients referred for angiographic evaluation of chest pain. Technically adequate two-dimensional echocardiograms suitable for analysis were recorded in 42 of 54 (77.7%) patients studied. Thallium-201 myocardial perfusion scintigraphy, during dipyridamole test was performed in the same patients. Thirty of the 42 patients studied showed significant coronary narrowing at cardiac catheterization. Dipyridamole-induced wall motion abnormalities and myocardial perfusion defects were detected, respectively, in 19 (63.3%) and 21 (70%) of 30 patients with significant coronary artery disease. Wall by wall comparison of the distribution of dipyridamole-induced echocardiographic asynergy with reversible thallium-201 (201Tl) perfusion defects demonstrated complete correlation in 42 segments examined. Three segments with perfusion defects at thallium scanning did not show asynergy during the test while two segments showing wall motion abnormalities during dipyridamole infusion did not manifest perfusion defects. Our study demonstrates that two-dimensional echocardiography during dipyridamole testing is useful in detecting patients with coronary artery disease. Furthermore, ventricular asynergies detected during the test show a high correspondence with site of myocardial perfusion defects at thallium scanning.

Cardiac Catheterization↗

Effect of mexiletine on reperfusion-induced ventricular arrhythmias: comparison with lidocaine.

Thirty mongrel dogs underwent proximal occlusion of the left anterior descending coronary artery to evaluate the comparative action of mexiletine and lidocaine on ventricular arrhythmias during myocardial reperfusion. Heart rate, arterial blood pressure, left ventricular end-diastolic pressure and dp/dt max were evaluated before and at the 20th and 25th min after coronary occlusion; at the 25th min coronary occlusion was removed. Dogs were randomly assigned to one of the following groups of 10: 1) control group; 2) dogs given i.v. mexiletine; 3) dogs given i.v. lidocaine. As expected, during ischemia, myocardial contractility decreased after mexiletine or lidocaine administration more than in the control group. Ventricular arrhythmias during myocardial reperfusion occurred in 9 dogs of the control group (ventricular tachycardia in 2 cases and ventricular fibrillation in 7 cases). Among dogs given mexiletine only 1 had ventricular fibrillation (p less than 0.001 vs control). Six of the 10 dogs given lidocaine had ventricular arrhythmias (ventricular tachycardia in 5 cases and ventricular fibrillation in 1 case) (p = ns vs control group; p less than 0.05 vs mexiletine group). Thus mexiletine and lidocaine had similar effects on cardiac function during myocardial ischemia and only mexiletine showed a protective effect against reperfusion ventricular arrhythmias.

Animals↗

Efficacy and pharmacokinetics of gallopamil in patients with coronary artery disease.

We prospectively studied 10 patients with stable exertional ischaemia, selected from a larger group of patients referred for suspected coronary artery disease or to detect residual ischaemia after myocardial infarction, to evaluate pharmacokinetic changes during chronic treatment with gallopamil and its correlation with clinical efficacy in patients with coronary artery disease. Our study consisted of a 1-week run-in single-blind placebo treatment and a 4-week single-blind gallopamil treatment. At the end of the run-in period patients underwent two different exercise tests, the first 2 hours and the second 7 hours after placebo administration. During active treatment all patients underwent two different exercise tests, the first 2 hours and the second 7 hours after gallopamil (50 mg) administration on the 1st and 28th days of gallopamil therapy. On the same days in eight of the patients we evaluated gallopamil pharmacokinetic changes. Our data revealed a rapid increase of unchanged gallopamil and its metabolite (norgallopamil) in the plasma, and a peak concentration of these substances about 2 hour after oral administration on both the 1st and 28th day of observation. Moreover, our results demonstrated an increase between the first and 28th day of treatment in peak concentration of unchanged gallopamil in the plasma, and of AUC 0-infinity and AUC o-c values during chronic treatment with gallopamil. Our clinical data showed an improvement in exercise results during gallopamil therapy related to increased concentration of the drug.

Aged↗

Choroidal angiography with indocyanine green dye: absorption and fluorescence techniques.

The results of choroidal indocyanine green (I.C.G.) angiography by the absorption and fluorescence techniques are compared. Both techniques were done using the same apparatus, a modified fundus camera, an image intensifier coupled to a solid-state video camera and a U Matic video recorder. Both were performed with the same dye dilution in the same patients, at a 24-hour interval. The light source was the unmodified 50 Watt halogen light bulb of the fundus camera. The angiograms obtained by the absorption and the fluorescence techniques refer to the same chorioretinal area and the same angiographic phase. Comparison of all the angiograms shows that I.C.G. fluorescence angiography provides a better resolution of choroidal vascular details than the absorption technique.

Choroid↗

[Radiologic examination of the paranasal sinuses in asthmatic children].

We examined the prevalence of abnormalities found by sinus X-Rays in 80 asthmatic children classified into three groups in relation to severity of their symptoms. All the children underwent skin tests and some of them methacholine challenge. 63.7% of asthmatics showed abnormalities in sinus X-Rays. No correlation was found between the severity of asthma, radiographic findings, and atopic status. Bronchial hyperreactivity studied using metacholine challenge according to the method of Chai was the same both in patients with asthma and sinusitis and in those with asthma only. In conclusion, abnormal sinus X-Rays do not seem to be an aggravating factor in asthmatic status.

Asthma↗