AAIR versus DDDR pacing in the bradycardia tachycardia syndrome: a prospective, randomized, double-blind, crossover trial.

In 19 patients paced and medicated for bradycardia tachycardia syndrome (BTS), AAIR and DDDR pacing were compared with regard to quality of life (QoL), atrial tachyarrhythmia (AFib), exercise tolerance, and left ventricular (LV)function. Patients had a PQ interval < or = 240 ms during sinus rhythm, no second or third degree AV block, no bundle branch block, or bifascicular block. In DDDR mode, AV delay was optimized using the aortic time velocity integral. After 3 months, QoL was assessed by questionnaires, patients were investigated by 24-hour Holter, cardiopulmonary exercise testing (CPX) was performed, and LV function was determined by echocardiography. QoL was similar in all dimensions, except dizziness, showing a significantly lower prevalence in AAIR mode. The incidence of AFib was 12 episodes in 2 patients with AAIR versus 22 episodes in 7 patients with DDDR pacing (P = 0.072). In AAIR mode, 164 events of second and third degree AV block were detected in 7 patients (37%) with pauses between 1 and 4 seconds. During CPX, exercise duration and work load were higher in AAIR than in DDDR mode (423+/-127 vs 402+/-102 s and 103+/-31 vs 96+/-27 Watt, P < 0.05). Oxygen consumption (VO2), was similar in both modes. During echocardiography, only deceleration of early diastolic flow velocity and early diastolic closure rate of the anterior mitral valve leaflet were higher in DDD than in AAI pacing (5.16+/-1.35 vs 3.56+/-0.95 m/s2 and 69.2+/-23 vs 54.1+/-26 mm/s, P < 0.05). As preferred pacing mode, 11 patients chose DDDR, 8 patients chose AAIR. Hence, AAIR and DDDR pacing seem to be equally effective in BTS patients. In view of a considerable rate of high degree AV block during AAIR pacing, DDDR mode should be preferred for safety reasons.

The significance of high levels of lipoprotein (a) compared with established risk factors in premature coronary artery disease: differences between men and women.

It was shown in a series of studies that increased lipoprotein (a) concentration is a strong and independent risk factor for coronary artery disease. The goal of this study was to determine the significance of elevated lipoprotein (a) levels for the existence and the early manifestation of coronary artery disease by systematically recording cardiovascular risk factors in diagnostic coronary angiographies in a larger group of patients, whereby particular attention was paid to sex-specific differences. In 1011 consecutive patients who underwent coronary angiography (731 men, 280 women, mean age 59 +/- 10 years), fasting blood samples were taken immediately before the angiographies to determine the levels of cholesterol, low density lipoprotein-, high density lipoprotein-cholesterol, triglycerides and lipoprotein (a). In addition, further risk factors were qualitatively recorded. The data evaluation was carried out using the SPSSx software package univariately and multivariately with stepwise discriminant analysis. In 231 patients (144 men, 87 women) either no or only discrete coronary findings appeared, while in 780 cases (587 men, 193 women) coronary artery disease with stenoses > 50% were found. Women with coronary artery disease were significantly older than men and demonstrated higher lipoprotein levels. Women as well as men with coronary artery disease differed from healthy controls by having higher levels of lipoprotein (a) and other lipoproteins, lipoprotein (a) having the smallest error probability (P < 0.0005). The early manifestation of coronary artery disease (below the 18th age percentile) in men (< 50 years) was connected with significantly higher levels of cholesterol, triglycerides and lipoprotein (a), which emphasized their atherogenic significance in the general view. The most striking finding was that in young women (< 53 years), compared to older women with coronary artery disease--corresponding to the age-determined prevalence--significantly lower concentrations of cholesterol, triglycerides and lipoprotein (a) were found. Possible explanations include later manifestation of coronary artery disease, a steeper increase of the lipids with age, particularly of lipoprotein (a), but also a different valence of the risk factors in women.

Femoral injection of echo contrast medium may increase the sensitivity of testing for a patent foramen ovale.

OBJECTIVE: The diagnosis of a patent foramen ovale (PFO) as a cause of stroke is of increasing interest especially in young (<45 years) patients. METHODS: We studied potential right-to-left shunting using transesophageal echocardiography (TEE) and bilateral transcranial Doppler sonography (TCD) of the middle cerebral artery (MCA) simultaneously in 44 patients. All patients were younger than age 45 years and suffered from an acute ischemic stroke or transient ischemic attack. Other possible etiologies were excluded. Echo contrast medium was injected in an alternating mode via antecubital or femoral veins. Tests were performed with and without the Valsalva maneuver. The criteria for a PFO were that the contrast pass from the right to the left atrium (TEE) and early detection (<10 seconds) of more than 10 micro air bubbles in at least one MCA by TCD. RESULTS: A PFO was diagnosed in 22 patients (50%). The detection rate with TEE/TCD was 11.4%/4.5% via antecubital injection, 18%/13.6% via antecubital injection plus the Valsalva maneuver, 38.6%/36% via femoral injection alone, and 50%/50% via femoral injection plus the Valsalva maneuver. The difference between femoral and antecubital injections was significant with and without the Valsalva maneuver (p < 0.01, chi2 test). There were no differences between TEE and TCD after femoral injection with the Valsalva maneuver. The brain transit time was 4.6 +/- 2.1 seconds for femoral injection and 6.3 +/- 4.1 seconds for antecubital injection. CONCLUSIONS: The sensitivity in detecting a PFO was markedly increased by femoral injection. This may be caused by different inflow patterns to the right atrium: inferior vena caval flow is directed to the right atrial septum, whereas superior vena caval flow is directed to the tricuspid valve. Thus, femoral injection may help to improve the detection of PFO and may explain the differences between TEE and TCD findings in previous studies.

[Cardiac function and the skin microcirculation in acromegaly]. / Kardiale Funktion und kutane Mikrozirkulation bei Akromegalie.

The microcirculation was measured by nail-fold capillary video microscopy in 21 patients (12 men, 9 women; mean age 54.7 [29-74] years) with acromegaly. Levels of growth hormone (12.0-71.7 microU/ml) and of somatomedin C (2.4-10.5 IU/ml) were elevated in 10 patients, despite preceding treatment. Eleven patients had an increase in myocardial thickness and nine had impairment of left ventricular function, although only slight in most. Left ventricular hypertrophy was demonstrable even in the absence of hypertension. No patient had evidence of coronary heart disease. Nail-fold capillary video microscopy (capillary density, torque index, reactive hyperaemia, epidermal blood flow) failed to distinguish between successfully treated patients and those with persistently elevated growth hormone concentrations or disease duration of over 5 years. There was no evidence of inadequate capillary blood flow as a cause of abnormal function in hypertrophied organs.