Posters

CAR-13

Evaluation of thyroid dysfunction in patients with paroxysmal atrial

fibrillation

G Picardi, P Vergara, F Scafuro, A Guarino, E Stampati, G Trinchese,

LA Napolitano, G Vergara

Division of Cardiology and Intensive Care Unit-Nola Hospital,

Nola /NA, Italy

Introduction: Atrial fibrillation (AF) is the most frequent cause of

hospitalization for arrhythmias. According to the data of the Framingham

study and of the Cardiovascular Health study, AF prevails 0.5% to 1% in

the general population with exponential growth related to age. The aim of

our study was to evaluate the prevalence of hyperthyroidism in patients

with episodes of AF without any cardiomyopathy.

Methods: Two hundred sixty-eight patients (164 women and 104 men,

64.9F 16.9) affected by paroxysmal AF were included in the present study.

Patients underwent routine laboratory exams, dosages of thyroid hormones,

standard ECG, and transthoracic echocardiography.

Results: TSH levels were low (b0.3 mU/L ) in 168 patients (62.7%) and

high (N5 mU/L) in 39 patients (14.9%); 76 patients (28.4%) had high FT3

levels (N 4.3 pg/mL), 91 patients (34.3%) had high FT4 levels

(N1.7 ng/dL), 60 patients (22.4%) had low FT3 levels (b2 pg/mL), and

24 patients (9%) had low FT4 levels (b0.9 ng/dL). Of the patients with

hyperthyroidism, 76.2% were women. Hyperthyroidism was considered

subclinical in 40.5% of patients.

Conclusions: Thyroid dysfunctions have an high prevalence in patients with

AF. Hyperthyroidism is the most common disorder. Hyperthyroidism in

patients with AF is more common in women than men. These data induce us

to take into consideration that also any minimal but persistent modification

of circulating thyroid hormone levels can favor episodes of AF; and so, in

depth examination of thyroid function in all patients with AF can be useful.

doi:10.1016/j.jelectrocard.2007.03.168

CAR-14

The training effects on autonomic nervous activity during head-up tilt

Machiko Yamamoto, Makiko Sato

School of Nursing, Miyagi University, Sendai, Miyagi, Japan

Introduction: Decreased baroreflex sensitivity (BRS) and high-frequency

component (HF) of heart rate variability (HRV) are believed to be signs

of poor prognosis, reflecting increased incidences of sudden cardiac

death in patients with cardiovascular diseases. We studied the training

effects on autonomic nervous activity during head-up tilt (HUT) by

evaluating spontaneous BRS and HRV without infusion of vaso-

active drugs.

Methods: Twenty healthy volunteers (mean age, 21 F 1.5years) were

enrolled in the study. They were divided into 2 groups. Group A is

composed of 9 females without physical exercise, and group B is

composed of 11 females with several occasions of physical exercise a

week. After a 15-minute rest period in supine position, HUTs

(15 minutes, 758) were performed. Before and during HUT, blood

pressure (BP) and ECG were monitored. Blood pressure was measured

using the tonometry method as a noninvasive and continuous BP

monitor. For analysis of the 5-minute records in resting position and

during HUT, the computer-selected sequences of 3 or more successive

heart beats were analyzed in which there were concordant increases or

decreases in systolic BP (SBP) and RR interval. If the correlation

coefficient between SBP value and RR intervals had a value less than

0.9, the data were discarded from the analysis. A linear regression

analysis was applied to each of the sequences, and an average regression

slope was calculated. This slope represents BRS (ms/mm Hg). The HRV

was also analyzed in the 5-minute records of resting position and during

HUT using the CGSA method.

Results: Results were shown in the table.

Conclusions: In group B, HF and BRS at resting position were preserved,

and increases of HR and LF/HF during HUT were controlled. The results

indicate that mild physical exercise training might preserve parasympathetic

nervous reserve, and control increased sympathetic nervous activities. In

addition, these physical exercise training might improve a poor prognosis

and decrease incidences of sudden cardiac death in patients with

cardiovascular diseases.

doi:10.1016/j.jelectrocard.2007.03.169

CAR-15

Baroreflex sensitivity is reduced in patients with recurrent

symptomatic atrial fibrillation

Katarzyna Styczkiewicz, Giammario Spadacini, Massimo Tritto,

Mario Facchini, Gianbattista Perego, Grzegorz Bilo,

Paolo Castiglioni, Kalina Kawecka-Jaszcz,

Jorge Antonio Salerno-Uriarte, Gianfranco Parati

IAI and Jagiellonian University, Milan, Cracow, Italy

Clinical Ist Mater Domini, Castellanza, Italy

Osp S Luca IAI, Milan, Italy

Bioengineering Centre Fondaz don Gnocchi, Milan, Italy

Jagiellonian Univ Medical College, Cracow, Poland

Circolo Hosp Macchi Foundation, Varese, Italy

Univ Milano-Bicocca, IAI, Milan, Italy

Introduction: An impaired baroreflex function is associated with derange-

ments in cardiovascular variability and with adverse cardiovascular

outcome. Little is known on the relation between atrial fibrillation (AF)

recurrence and cardiac baroreflex modulation. This study aimed at

investigating whether baroreflex sensitivity (BRS) is related to frequency

of paroxysmal symptomatic AF recurrence.

Table 1

HR

(beat/min)

SBP

(mm Hg)

DBP

(mm Hg)

Rest HUT Rest HUT Rest HUT

Group A 64 F 6 84 F 8a 99 F 7 103 F 12 56 F 7 70 F 7a

Group B 59 F 4b 73 F 7a,b 96 F 3 103 F 7a 56 F 5 65 F 5a

Values are mean F SDa Rest vs HUT.b Group A vs group B.

P b .01.

Table 2

Log HF (ms2) Log LF/HF BRS (ms/mm Hg)

Rest HUT Rest HUT Rest HUT

Group A 2.5 F 0.3 1.8 F 0.2b 0.1 F 0.3 0.6 F 0.3a 22.5 F 8.1 7.5 F 2.6a

Group B 2.8 F 0.4b 2.1 F 0.3a,b 0.3 F 0.3b 0.3 F 0.5a 33.2 F 14.5 12.4 F 4.6a,b

Values are mean F SDa Rest vs HUT.b Group A vs group B.

P b .01.

Abstracts / Journal of Electrocardiology 40 (2007) S1–S77S18