PR Interval Adaptation in the Denervated Transplanted Heart

In the present study, the dynamic PR response upon standardized treadmill exercise was investigated in 21 transplant recipients (recipient age 48 ± 17 years, donor age 31 ± 12 years, > 1 year after transplantation). MR and PR interval were measured at rest and at the end of each 25-Wincrease in workload till peak exercise. In 17 cases norepinephrine (NE) was assessed at rest, and at the end of each workload the MR increased from 99.3 ± 14 to 143.4 ± 25 beats/min at individual peak exercise, and NE increased from 1.307 ± 1,163 to 3.688 ± 2.036 pg/mL. while the PR interval shortened from 149.2 ± 13 to 119.3 ± 20 ms. On average. PR decreased by 3.4 ms for a 10-beat increase in HR, and the HR-PR interval relationship was described by a linear regression (y = 176.8–0.3469x, P = 0.0001). One patient who was unable to increase his NE levels upon exercise showed virtually no decrease in the PR interval and no HR increase. Both recipient age and donor age were moderately and significantly related to the minimum PR interval achieved at peak exercise (r = 0.6. P = 0.008 and r = 0.51. P = 0.049, respectively). These data show the following: (1) adaptation of the PR interval upon exercise does occur in the denervated transplanted heart; (2) the HR-PR relation is similar to that reported in the innervated heart; (3) the overall decline in PR interval is blunted, since denervated patients start at shorter resting PR intervals and achieve relatively longer PR intervals at peak exercise when compared to their innervated counterparts; (4) these exercise induced changes of the PR interval may be explained by circulating NE; and (5) NE levels achieved at peak exercise and the sensitivity of the AV node to NE seem to be age related. (PACE 1997; 20[Pt. I]:1247-1251)     

Emotion Profiles and Quality-of-Life of Paced Patients

More than any other organ of human anatomy, the heart is symbolically charged with emotions. Introducing a foreign body into the heart, even a pacemaker, would be expected to alter, if not damage the most intimate of personal attributes, an individual's personality. Nevertheless, standard measures of emotions, administered before and after pacemaker implantation, revealed an improvement in psychological well-being in an unselected sample of 80 patients, aged 36 to 80 years. Furthermore, these results occurred whether or not patients returned to work.     

Sinus Node Dysfunction After Orthotopic Cardiac Transplantation: Postoperative Incidence and Long-Term Implications

We investigated incidence, normalization rates, and clinical significance of sinus node (SN) dysfunction after cardiac transplantation. Thirty-nine of 90 patients systematically evaluated presented with impaired SN function in the postoperative period. Of these, 22 normalized their SN function during follow-up while 17 remained impaired after 3 months. The proportion normalized was higher in patients with prolonged SN recovery time (11/16, 68.8%) and those reverting from escape rhythm to sinus rhythm until discharge (5/8, 62.5%) when compared to patients in escape rhythm throughout the postoperative period (5/11, 45.5%) or pacemaker dependence (1/4, 25%). There was no reliable postoperative predictor of normalization and necessity of long-term pacing. A postoperative heart rate consistently less than 70 beats/min (irrespective of the native rhythm) was significantly related to outcome (P = 0.01), but revealed unacceptable sensitivity (61.5%) and specificity (81%). After all, both patients with severe symptoms (near syncopes and syncope), were derived from this group. These two patients, who had been discharged in sinus rhythm, had late pacemakers implanted. An additional 17 patients had early pacemaker placement, only seven of which were constantly paced during follow-up. Given the low normalization rates, patients with postoperative escape rhythm are those most likely to benefit from pacemaker therapy over the long term. Even those in, or reverting back to, sinus rhythm until discharge may experience severe symptoms, particularly in the setting of a postoperative rate consistently less than 70 beats/min since this indicates a relatively lower probability of recovery.     

Keratoacanthoma and multiple carcinomas

A case of keratoacanthoma, preceding four primary malignant tumours without metastasis, is presented. Two similar cases from the literature with two and three multiple primary carcinomas, are reviewed. They all have the following findings in common: (1) keratoacanthoma, (2) adenocarcinoma of the colon, (3) additional primary malignant tumour or tumours, and (4) absent or delayed metastasis.