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Katya Reis-Santos

Publications and source records attributed to Katya Reis-Santos.

7 recordsLinked to original sources
PubMed2005

Hybrid approach to severe coarctation and aortic regurgitation.

Aortic coarctation is occasionally detected only in adulthood, usually in the context of systemic hypertension. It is frequently associated with other malformations, but the presence of severe disease of the aortic or mitral valves is rare. Such associated lesions, nonetheless, have important implications regarding the type and timing of therapeutic interventions. We describe an adult patient with severe aortic coarctation, aortic valvar regurgitation, and impaired left ventricular systolic function. We treated the aortic coarctation first by means of percutaneous dilation and implantation of a stent. Four days later, we proceeded to treat the aortic regurgitation surgically, using the Bentall procedure. Our experience documents a safe and efficient therapeutic approach to this association of lesions.

Adult↗
PubMed2005

Ventricular tachycardia ablation in patients with coronary heart disease: beyond the reentry circuit.

INTRODUCTION: Patients with coronary heart disease and left ventricular dysfunction are at increased risk for the development of ventricular tachycardia (VT) related to areas of myocardial fibrosis. Although the mechanism and the circuit of this arrhythmia are well understood, little is known about the triggers that precipitate VT episodes. Purkinje fiber potentials may be responsible for idiopathic VT, and recent studies have related them to polymorphic VT and ventricular fibrillation. METHODS: Between January 2002 and December 2003, we performed ablation in 10 patients with coronary heart disease, left ventricular systolic dysfunction and VT refractory to pharmacological therapy. All patients had implantable cardioverter-defibrillators. Electroanatomical activation and voltage mapping (CARTO) and electrophysiological criteria (premature activation during VT, pace mapping, and presence of diastolic potentials) were used to define scar regions, slow conduction areas and the reentry circuit isthmuses. RESULTS: Spike potentials were recorded in the scars of three patients. These potentials were almost fused with the ventricular electrogram during sinus rhythm, and were more premature during VT, probably reflecting local activation of Purkinje fibers. During ablation, we were able to dissociate the spike from the ventricular electrogram, thus terminating the VT. In the cases with conduction recovery, ventricular; ectopic beats recurred, preceded by a spike and degenerating into short runs of VT. The ablation strategy was not modified since persistence of the VT required the isthmus. CONCLUSION: The results suggest that residual Purkinje fibers may be present in scar regions and that the activity of these fibers may trigger VT in pre-established circuits.

Catheter Ablation↗
PubMed2004

Atrial tachycardia ablation in a patient with double outlet right ventricle corrected by surgery.

The development of surgical and percutaneous techniques for treatment or palliation of congenital heart disease has prolonged survival in these patients and has increased late complications, particularly arrhythmias. Such arrhythmias are more frequently refractory to medical therapy, requiring percutaneous ablation. We present the clinical case of a 14-year-old child with complex congenital heart disease (double outlet right ventricle) who underwent two corrective surgeries (Rastelli operation and subsequent replacement of the homograft in the conduit connecting the right ventricle to the pulmonary artery; ventricular septal defect closure and tricuspid valve repair). After the second surgery the patient presented with wide complex syncopal tachycardia, refractory to medical therapy. Electrophysiologic study (EPS) identified an isthmus-dependent atrial flutter that was successfully treated by radiofrequency (RF) ablation (a linear block was created along the cavo-tricuspid isthmus). Three months later a new episode of tachycardia occurred, but without syncope. The second EPS revealed an atrial tachycardia originating from the lateral wall of the right atrium, which was treated by ablation with focal application of RF energy. Four months after the last EPS the child remains free of arrhythmic symptoms, under no anti-arrhythmic therapy.

Adolescent↗
PubMed2004

Atrial flutter ablation: correlation between isthmic activation times and flutter cycle.

BACKGROUND: Ablation of typical atrial flutter relies on the suppression of electrical conduction along the cavo-tricuspid isthmus. Bidirectional isthmus block is a criterion of successful ablation and is associated with the presence of different activation times on each side of the ablation line. OBJECTIVE: The aim of this study was to determine whether the difference in isthmic activation times correlates with the length of the atrial flutter cycle. POPULATION AND METHODS: We studied 31 patients with typical atrial flutter (93.6% male, mean age 66 +/- 9 years) who underwent successful ablation during tachycardia. CARTO electroanatomic mapping was used to confirm diagnosis of isthmus-dependent atrial flutter, guide the ablation line creation and assess its efficacy. At the end of the procedure, a three-dimensional activation map of the right atrium was constructed, under pacing from the coronary sinus ostium (with a 500 ms cycle). Activation times on the lateral (right) and septal (left) sides of the ablation line were measured. The difference between these two activation times was termed the difference in isthmic activation times (delta IAT), and was compared to the flutter cycle length. RESULTS: Mean activation times were 173.7 +/- 34.3 ms on the lateral border of the ablation line and 19.1 +/- 12.5 ms on the septal border. Mean delta IAT was 154.6 +/- 27.8 ms and mean atrial flutter cycle length was 257.5 +/- 30.6 ms. delta IAT and flutter cycle length were significantly correlated (r = 0.503, p = 0.0039). The linear regression equation that best described this result was: delta IAT = 37 + (0.46 x flutter cycle). CONCLUSION: After atrial flutter ablation, a difference in isthmic activation times of more than half the flutter cycle length was associated with isthmus conduction block.

Aged↗
PubMed2003

Electrical disconnection versus anatomical isolation of the pulmonary veins: two sides of the same treatment for atrial fibrillation?

OBJECTIVE: There are currently two techniques for percutaneous electrical isolation of the pulmonary veins (PV): anatomical isolation and electrical disconnection. The aim of the present study was to assess the continuity and circumferential extension of the radiofrequency applications necessary for PV electrical disconnection in order to evaluate the differences between this technique and anatomical isolation. METHODS: We studied 9 patients with paroxysmal atrial fibrillation who underwent PV electrical disconnection. The electrophysiologic study was performed with a decapolar circular catheter (Lasso) introduced in the PV ostia and a mapping and ablation catheter (CARTO). Ablation was performed following the activation sequence of PV potentials. Using the CARTO system we evaluated the number of applications, their distribution in quadrants, and the maximum distance between contiguous and opposite RF applications. We assessed the number of veins with circumferential applications. The number of applications and maximum distance between contiguous applications were compared to the maximum distance between opposite applications. RESULT: A total of 26 PV were isolated, including 9 right superior, 5 right inferior, 6 left superior and 6 left inferior. On average more than 10 applications were necessary, with a heterogeneous distribution. In 80.8% of the PVs the maximum distance between contiguous application was less than 1 cm and maximum distance between opposite application were highest in the right superior PV and lowest in the right inferior PV. The applications were circumferential in 80.8% of the disconnections. The number of RF applications was significantly higher in PVs with greater distances between opposite applications (correlation coefficient 0.51; p=0.008). No relation was found between maximum distances in contiguous and opposite applications (correlation coefficient r=0.13; p=NS). CONCLUSION: Electrical disconnection was achieved in the great majority of cases with circumferential applications, similarly to anatomical isolation. However, the heterogeneous distribution of the applications implies the existence of areas that need a greater number of applications and that can only be identified during electrophysiologic study. Therefore, rather than two aspects of the same treatment for atrial fibrillation, electrical disconnection and anatomical isolation complement each other in the achievement of effective PV isolation.

Adult↗
PubMed2002

Influence of prior medication on mode of presentation and prognosis of acute coronary syndromes.

OBJECTIVES: To evaluate the influence of prior medication on mode of presentation and short-term prognosis of acute coronary syndromes (ACS). DESIGN: Prospective study. SETTING: Coronary intensive care unit in Santa Cruz Hospital. POPULATION: We included 425 consecutive patients admitted for ACS. METHODS: Prior medication with anti-platelet agents, beta-blockers, nitrates, calcium channel blockers, statins and angiotensin-converting enzyme (ACE) inhibitors was recorded on admission. Medication introduced in the last 7 days was excluded. Using a multivariate analysis model we examined the impact of baseline characteristics and previous medication on mode of presentation of ACS. We also evaluated their influence on short-term prognosis (death or non-fatal myocardial (re)infarction in the first 30 days). RESULTS: Of the 425 patients studied 228 (53.6%) presented with unstable angina (UA), the remainder with acute myocardial infarction (AMI) (24.7% with ST elevation). Medication prior to admission included anti-platelet agents in 53.7% of patients, beta-blockers in 44.2%, nitrates in 48.2%, calcium channel blockers in 36.9%, statins in 28.9% and ACE inhibitors in 38.6%. During the first 30 days, 14 deaths (3.3%) and 37 (re)infarctions (8.7%) occurred. The combined occurrence of death or (re)infarction was 10.8%. Variables with significant and independent influence on mode of presentation of ACS were male gender, presence of known coronary artery disease and previous medication with anti-platelet agents and beta-blockers. Male gender was a predictor of AMI as mode of presentation, whereas a previous history of coronary artery disease and medication with anti-platelet agents or beta-blockers predicted UA. Short-term prognosis was influenced by heart failure symptoms on admission, but not by previous medication. CONCLUSION: Previous medication with anti-platelet agents and beta-blockers was associated with an increased frequency of UA as mode of presentation of ACS. No relation between previous medication and short-term prognosis was observed in the present study.

Adrenergic beta-Antagonists↗