Armando Gardini

Rate of progression of valvular aortic stenosis in adults

Until recently the hemodynamic severity of valvular aortic stenosis (AS) was evaluated only by cardiac catheterization. Now, Doppler echocardiography allows a noninvasive and accurate assessment of AS severity and can be used to study its progression with time. The progression of AS was assessed during a follow-up period of 6 to 45 months (mean 18) by serial Doppler examinations in 45 adult patients (21 men and 24 women, mean age 72 +/- 10 years) with isolated AS. The following parameters were serially measured: left ventricular outflow tract diameter and velocity by pulsed Doppler, peak velocity of aortic flow by continuous-wave Doppler, to calculate peak gradient by the modified Bernoulli equation, and aortic valvular area by the continuity equation. At the initial observation, 13 of 45 patients (29%) were symptomatic (1 angina, 1 syncope and 11 dyspnea); during follow-up, 25 (55%) developed new symptoms or worsening of the previous ones (5 angina, 3 syncope and 17 dyspnea); 11 underwent aortic valve replacement and 3 died from cardiac events. Baseline peak velocity and gradient ranged between 2.5 and 6.6 m/s, and 25 and 174 mm Hg, respectively; aortic area ranged between 0.35 and 1.6 cm2. With time, mean peak velocity and gradient increased significantly from 4 +/- 0.7 to 4.7 +/- 0.8 m/s (p less than 0.01), and 64 +/- 30 to 88 +/- 30 mm Hg (p less than 0.01), respectively. A concomitant reduction in mean aortic area occurred (0.75 +/- 0.3 to 0.6 +/- 0.15 cm2; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Mechanisms and Immediate Outcome of In-Hospital Cardiac Arrest in Patients With Advanced Heart Failure Secondary to Ischemic or Idiopathic Dilated Cardiomyopathy

To differentiate patients with congestive heart failure who are more prone to develop malignant ventricular tachyarrhythmias or severe bradyarrhythmias as the terminal event, we retrospectively evaluated a group of 48 patients with advanced heart failure who experienced a monitored cardiac arrest during hospital stay. We found no significant differences with respect to several variables, apart from clinical status, which was worse in patients whose cardiac arrest was precipitated by severe bradycardia or electromechanical dissociation.

Blind Extrathoracic Subclavian Venipuncture for Pacemaker Implant: A 3-Year Experience in 250 Patients

We report our 3‐year experience using a modification of the percutaneous technique for extrathoracic subclavian Venipuncture proposed by Magney and colleagues for permanent pacing lead placement. Before surgery bony landmarks were marked on the skin according to Magueys description to identify the needle entry point and the target point corresponding to the ideal location of the extrathoracic portion of the subclavian vein. Then the venipuncture was accomplished by inserting the needle through a standard infraclavicular pacemaker pocket. Two hundred fifty patients undergoing primary pacemaker implant (231 patients) or reimplant or change of mode of pacing (19 patients) were included in the study. The technique was successful in 245 (98%) cases. Inadvertent puncture of the subclavian artery occurred in 5 (2%) patients but in no case did it jeopardize the success of the implant procedure. No major complications were observed. Seven (2.9%) patients experienced early complications unrelated to the venous approach: 2 subclavian vein thrombosis, 5 lead dislodgment in 4 patients, and 1 pocket hematoma. During a mean follow‐up of 15.2 months (range 4–40) no lead or patient related complications occurred. In the present study the blind approach to the extrathoracic portion of the subclavian vein proved to be safe and effective for pacing lead insertion. Further observations are required to establish whether this method extends the lead survival.

Torsade de pointes occurring early during oral amiodarone treatment

Amiodarone is reported to have a low incidence of proarrhythmic effects. They generally occur during chronic treatment in association with increase in amiodarone dosage, electrolyte disorders, or concomitant therapy with class IA antiarrhythmic drugs. We describe a case of amiodarone-induced torsade de pointes early after initiation of low-dose oral therapy, in absence of other predisposing factors.

Implantable defibrillation and thromboembolic events.

In ICD patients thrombo‐embolic events (TEEs) are described as possible complications at implant or during the follow‐up. We report four cases of TEEs (two peripheral and two cerebral; 6.5% of patients) that occurred in our series during a mean follow‐up of 19.4 months. The patients had chronic postinfarction LV aneurysm (3) and idiopathic dilated cardiomyopathy (1). None had previous embolisms nor evidence of left atrial or LV clots at standard preoperative transthoracic echocardiography. No paroxysms of atrial fibrillation were documented prior or after ICD implant. We discuss the possible causes of embolization and the suitability of anticoagulant therapy in ICD patients.

Congestive Heart Failure in Patients with Valvular Aortic Stenosis

The aim of this study was to evaluate echographically anatomic and functional features of the left ventricle in adult patients with valvular aortic stenosis according to the presence or absence of congestive heart failure and the level of ventricular performance. Fifty-six adult patients with moderate-to-severe aortic stenosis underwent echocardiographic Doppler examination in order to evaluate left ventricular mass and dimensions, systolic function and filling dynamics. Twenty-seven patients had no heart failure and were symptomatic for angina (5), syncope (4) or were symptom-free (group I); the other 29 had heart failure (group II): 16 with normal left ventricular systolic performance (fractional shortening > 25%, group IIa) and 13 with systolic dysfunction (fractional shortening < or = 25%, group IIb). Despite a similar left ventricular mass, compared to group IIa, group IIb showed a significant left ventricular dilatation (end-diastolic diameter: 61 +/- 6.5 vs. 45.5 +/- 6.1 mm, p < 0.001) and mild or no increase in wall thickness (11.5 +/- 1.6 vs. 14.9 +/- 2 mm, p < 0.001). Indices of left ventricular filling on Doppler transmitral flow were also significantly different between the two groups, with a higher early-to-late filling ratio and a shorter deceleration time of early filling in group IIb (2.8 +/- 1.9 vs. 1.2 +/- 0.85, p < 0.01, and 122 +/- 66 vs. 190 +/- 87 ms, p < 0.05, respectively), both indirectly indicating higher left atrial pressure. Finally, heart failure was generally more severe in group IIb patients. In some patients with aortic stenosis, symptoms of heart failure may be present despite a normal left ventricular systolic function and seem to depend on abnormalities of diastolic function. The presence of systolic or isolated diastolic dysfunction appears to be related to a different geometric adaptation of the left ventricle to chronic pressure overload.

Diagnostic capabilities of devices for cardiac resynchronization therapy.

Atrial fibrillation and chronic heart failure often coexist. Asymptomatic atrial fibrillation is common in patients with known atrial fibrillation but also in patients with no history of previous atrial fibrillation. The enhanced diagnostic capabilities of modern implantable devices for cardiac resynchronization therapy allow collecting of data on the clinical status of the patient in addition to information on device performance and cardiac rhythm. We present a paradigmatic case of newly diagnosed atrial fibrillation with hemodynamic consequences detected by the diagnostics of a biventricular implantable cardioverter-defibrillator. We discuss the clinical utility of device-based monitoring and the potential advantages of wireless remote-control systems of implantable devices in the management of heart failure patients.

Regression of warfarin-resistant left atrial appendage thrombus after ablation of atrial fibrillation and permanent pacing.

Atrial fibrillation is the most common rhythm disturbance and can also occur in absence of true cardiac disease. However, also in these cases, it can generate left atrial appendage thrombi with systemic embolic potential. A regular and well conducted anticoagulant therapy with dicoumarol derivatives, as indicated in these patients, is not always successful. We report the case of a patient with lone atrial fibrillation and a left atrial appendage thrombus resistant to anticoagulant therapy with warfarin, which disappeared after catheter ablation of atrial fibrillation by electrical disconnection of the pulmonary veins, restoration of sinus rhythm and dual-chamber pacemaker implantation.

Clinical feasibility of low energy internal atrial cardioversion with a three-electrode configuration in patients with unsuccessful conventional configurations.

Low energy internal cardioversion is a safe and highly effective method for atrial fibrillation termination. We will describe 6 patients in whom the conventional 2-electrode systems with the defibrillation leads positioned in the right atrium and in the coronary sinus or left pulmonary artery failed to terminate the arrhythmia despite the use of maximal available energies. A 3-electrode configuration including right atrium, coronary sinus and left pulmonary artery was used in order to encompass as much atrial mass as possible between the cathode and the anode. The atrial fibrillation was successfully interrupted in 4 out of 6 patients. The creation of a 3-electrode configuration may be a further technical expedient in order to increase the success rate of internal cardioversion when usual manoeuvres like lead repositioning, reversion of polarity, or addition of antiarrhythmic drugs are ineffective.