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Biomedical subjects

Alessandro Giardini

Publications and source records attributed to Alessandro Giardini.

27 records · Page 2Linked to original sources
PubMed2004

Recovery kinetics of oxygen uptake is prolonged in adults with an atrial septal defect and improves after transcatheter closure.

BACKGROUND: In adults with an atrial septal defect (ASD) transcatheter closure leads to an improvement of peak oxygen uptake (VO2), but the kinetics of recovery of VO2 after maximal exercise in this patient population and the impact of transcatheter ASD closure have never been investigated. METHODS: Twenty consecutive patients underwent a maximal cardiopulmonary exercise test both the day before and 6 months after transcatheter ASD closure. For comparison, an age- and sex-matched group consisting of 53 healthy adults was built. The constant decay of VO2, CO2 production (VCO2), minute ventilation (VE), and heart rate (HR), expressed as the first-degree slope of a single linear relation, were calculated for the first minute of recovery. RESULTS: Patients with an ASD had a prolonged VO2 slope (P =.0012), VCO2 slope (P =.0003), and VE slope (0.013) when compared with control subjects. Six months after transcatheter ASD closure, significant improvements of VO2 slope (P =.0043) and of VCO2 slope (P =.0022) were recorded, so that no difference was found when compared with those of the control group (P =.1 and P =.06, respectively). The VE slope and HR slope did not change after closure. A significant association between VO2 slope and peak VO2 in the group of patients with ASD was shown by the Spearman correlation, both before (r = 0.67, P =.0012) and after ASD closure (r = 0.71, P =.0004). CONCLUSIONS: A limited cardiopulmonary reserve in adults with no symptom who have an ASD appears to affect not only maximal exercise responses but also the recovery phase. Transcatheter ASD closure induces a significant improvement of the ability of recovering from maximal exercise and eliminates the difference with a healthy population.

Adolescent↗
PubMed2004

Effect of chamber capacitance on Doppler flow pattern across restrictive defects in obligatory atrial-level shunts.

The right atrium has a significantly higher capacitance than the left atrium, and this may affect the Doppler flow pattern across an atrial septal defect (ASD) in unilateral atrioventricular (AV) valve atresia. This Doppler flow pattern is often used to assess ASD adequacy in this setting. We studied the effect of atrial capacitance and ASD size on the trans-ASD Doppler flow pattern in an in vivo flow model of alternate left or right AV valve atresia (LAVVA and RAVVA). We assessed trans-ASD Doppler flow patterns using the max/min velocity ratio and mean interatrial pressure gradients (PGs). In both models, ASD flow rate correlated with mean trans-ASD PG, but for similar flow rates the slope was higher in the LAVVA model. In LAVVA, a persistent PG was consistently observed, with low max/min ratio (median, 1.46; range, 1.03-3.13), whereas in RAVVA, phasic flow was common (median, 8.0; range, 2.8-20). Because atrial capacitance affects mean PG and Doppler flow pattern across the ASD, we propose that the assessment of ASD adequacy in RAVVA should not rely on Doppler findings.

Animals↗
PubMed2004

Ipsilateral hemangioma and aortic arch anomalies in posterior fossa malformations, hemangiomas, arterial anomalies, coarctation of the aorta, and cardiac defects and eye abnormalities (PHACE) anomaly: report and review.

Posterior fossa malformations, hemangiomas, arterial anomalies, coarctation of the aorta, and cardiac defects and eye abnormalities (PHACE) is a rare congenital anomaly with a broad spectrum of clinical manifestations with a striking female predominance. We describe an infant with PHACE anomaly and aortic coarctation who underwent cardiac catheterization to clearly define the complex anatomy of the aortic lesion before surgical repair. Review of the literature documents a highly significant association between ipsilateral hemangiomas and cerebrovascular and aortic arch anomalies. We conclude that cardiac catheterization is required to define the complex anatomy of aortic lesions and should be performed in all patients with PHACE and evident aortic involvement to plan appropriate and safe surgical repair.

Abnormalities, Multiple↗
PubMed2003

Treatment of recurrent stroke and pulmonary thromboembolism with percutaneous closure of a patent foramen ovale and placement of inferior vena cava filter.

The association between recurrent episodes of pulmonary embolism, stroke, and congenital anomalies of the clotting system features a condition of increased risk of recurrences despite anticoagulant therapy. We report the successful management of this association with percutaneous closure of the foramen ovale and placement of an inferior caval vein filter.

Adult↗
PubMed2003

Intravenous flecainide for the treatment of junctional ectopic tachycardia after surgery for congenital heart disease.

BACKGROUND: Junctional ectopic tachycardia (JET) is a life-threatening arrhythmia producing severe hemodynamic dysfunction, which may complicate the postoperative course of surgery for congenital heart disease. Strict care and a fast and effective antiarrhythmic strategy are essential, because mortality largely depends on the duration of the arrhythmia. METHODS: Seven consecutive neonates with postoperative JET without any evidence of myocardial ischemia received intravenous flecainide after conventional therapies proved ineffective. Atrial pacing at the minimal rate for atrioventricular synchrony was followed by a 10-min intravenous infusion of 1.6 mg/kg flecainide, then continuous infusion of 0.4 mg/kg flecainide per hour. Treatment was considered effective based on restoration of sinus rhythm or a JET rate no higher than 170 bpm within 4 hours of flecainide loading. Overall mean flecainide infusion lasted 31.2 hours (range 25 to 53 hours). Side effects were assessed by monitoring plasma flecainide levels, electrocardiogram, arterial pressure, and central venous pressure. RESULTS: Flecainide was effective in all 7 patients after an infusion duration of 3.6 +/- 1.5 hours. Sinus rhythm was restored after 7.2 +/- 9.7 hours. After 4 hours of loading, heart rate fell from 219 +/- 14 to 136 +/- 7 bpm (p < 0.0001), arterial pressure increased from 69 +/- 8 to 93 +/- 10 mm Hg (p < 0.0001), while central venous pressure decreased from 8.0 +/- 1.6 to 5.2 +/- 1.9 mm Hg (p = 0.0007). No side effect or recurrence was noted. CONCLUSIONS: Flecainide can exert a fast antiarrhythmic effect on postoperative JET, and its infusion can be modulated to maintain the concentration within the therapeutic range, thus avoiding toxicity. We propose further consideration of flecainide for treatment of JET in neonates without myocardial ischemia.

Anti-Arrhythmia Agents↗
PubMed2003

Prevalence and predictors of neoaortic regurgitation after arterial switch operation for transposition of the great arteries.

BACKGROUND: The fate of the native pulmonary valve after arterial switch operation is still unknown and may become a cause for a secondary aortic valve operation during adult life. We evaluated the prevalence and predictive factors associated with neoaortic valvular regurgitation by a retrospective study of children who underwent arterial switch operation for transposition of the great arteries. METHODS: The onset of neoaortic valvular regurgitation was correlated with demographic data, cardiac anatomy, surgical technique, and postoperative ventricular function. The size of the neoaortic root and ascending aorta was measured in a selected subset of patients. RESULTS: Among 253 survivors, 173 were eligible for the study. After a median follow-up time of 8.2 years, 61 patients showed echocardiographic or angiographic evidence of valvular incompetence, which was progressive in 14 cases; this led to surgical intervention in 2 patients, and there was 1 operative death. At multivariate analysis, the onset of valvular regurgitation was correlated with the trap-door technique for coronary reimplantation (P <.01). A smooth transition from the aortic sinus to the ascending aorta, with loss of the normal sinotubular junction geometry, may be associated with valvular incompetence. CONCLUSIONS: After arterial switch operation, there is an increasing frequency of neoaortic regurgitation, which may lead to significant valvular dysfunction later in life. The trap-door type of coronary reimplantation is associated with an increased risk for valvular dysfunction, possibly because of a distortion of the sinotubular junction geometry. For this reason, we recommend the punch technique for repair in all but the most complicated coronary pattern.

Aortic Valve↗
PubMed2003

Modulation of neurohormonal activity after treatment of children in heart failure with carvedilol.

BACKGROUND: In adults with heart failure, neurohormonal overstimulation is related to the progression of the disease, and influences prognosis. beta-blockers, which modulate neurohormonal activation, now play an essential role in the pharmacological management of heart failure in adults, but their use in children is very limited. PATIENTS AND METHODS: To investigate the effects of carvedilol administration on neurohormonal activation and left ventricular function, carvedilol was added to standard treatment for heart failure in 9 patients with dilated cardiomyopathy due to heart muscle disease. Standard treatment has been in place for at least 1 month. The protocol consisted in a baseline evaluation to assess neurohormonal activation, and echocardiographic evaluation of left ventricular function. This was followed by a final evaluation at 12 months from carvedilol loading. Carvedilol was started at 0.05 mg/kg/day, and increased every two weeks until the target dose of 0.8 mg/kg/day was reached. RESULTS: Carvedilol administration was associated with a significant reduction in plasma norepinephrine (p = 0.00001), dopamine (p = 0.0001), aldosterone (p = 0.00001) and activation of the renin-angiotensin system (p = 0.0006). Similar reductions in vanilmandelic and homovanillic acid were noted. After 12 months, a positive remodeling took place, with significant reductions in end-diastolic (p = 0.004) and end-systolic diameters (p = 0.009), and an increase in left ventricular ejection fraction (p = 0.001). No adverse effects needing reduction or interruption in the dosage were noted in the run-in phase, nor in the period of maintenance. CONCLUSION: Carvedilol is a safe complement to standard therapy for heart failure in children, allowing a significant reduction of neurohormonal activation with evident benefits on both ventricular function and the clinical condition.

Adrenergic beta-Antagonists↗