Diltiazem prophylaxis reduces incidence of atrial fibrillation after coronary artery bypass grafting.

AIM: To evaluate the prophylactic effect of diltiazem on the incidence of atrial arrhythmia (fibrillation and/or flutter) following coronary artery bypass grafting (CABG). Data were retrospectively gathered. METHODS: Patients undergoing elective CABG by one surgeon at one institution over a three-year period were considered for inclusion. Those selected were divided into 3 groups: A (patients placed on intravenous diltiazem intraoperatively, then converted to oral diltiazem upon initiation of oral intake); B (patients started on oral diltiazem upon initiation of oral intake without prior intravenous diltiazem); and C (patients receiving no diltiazem). A comparison of postoperative rates of atrial fibrillation was made between the 3 (demographically balanced) groups using logistic regression. RESULTS: Two hundred and eighty seven patients met inclusion criteria. The incidence of postoperative atrial fibrillation in the entire sample was 19.9% (57/287). Incidence of postoperative atrial fibrillation within each group was: A = 16.3% (22/135); B = 12.7% (7/55); C = 28.9% (28/97). Statistical significance was demonstrated for the following comparisons: A versus C (p = 0.0451) and B versus C (p = 0.0065). In an alternate model groups A and B were combined and compared to C (p = 0.0181). CONCLUSIONS: A lower incidence of atrial fibrillation following CABG was observed in patients treated prophylactically with diltiazem. Differences were statistically significant whether the drug was administered intravenously and orally (A) or only orally (B). Diltiazem, which has an established role in the management of atrial fibrillation, may prove to be well suited for prophylaxis due to low cost and relative safety.

Venous bypass of complicated stent placement for recurrent extracranial carotid occlusive disease.

Aim of the study was to to demonstrate a useful solution to carotid angioplasty and stent complications. A 67 year old male had uncomplicated left carotid endarterectomies in 1985 and 1986. A left distal common carotid angioplasty and stent in 1999 was complicated by stenosis. In 2000 a left common carotid bypass from the lower common carotid to the distal internal carotid well above the stent was performed, yielding retrograde filling of the external carotid, distal antegrade filling of the internal carotid, and widely patent vessels in subsequent Doppler studies. He is currently doing well clinically with no recurrent stenosis. In conclusion a second redo carotid operation was deferred in favor of angioplasty and stent, which had complications. Despite prior operations the only difficulty with the reoperation was obtaining control of the distal internal carotid above the stent. The strategy demonstrated here will be useful to correct complications of carotid angioplasty and stenting.

Accuracy of implanted port placement with the use of the electromagnetic CathTrack catheter locator system.

PURPOSE: To test whether an electromagnetic guidance system such as CathTrack would allow long-term central venous access devices to be reliably placed at a decreased cost and without radiation exposure to patients and staff. The following study was undertaken to verify accuracy of the CathTrack system for catheter placement and to develop guidelines for its use. METHODS: Twenty-nine consecutive patients were prospectively enrolled in the study and taken to the operating room for implantation of a permanent central venous access port. By protocol, the CathTrack system was used to guide initial catheter positioning using the center of the third intercostal space along the right sternal border as the desired external target. Fluoroscopy was then used to visualize tip position and relocate the catheter tip to the exact position desired by the surgeon. RESULTS: Catheter placement using the CathTrack system was successfully accomplished in 27 out of 29 patients. In two instances CathTrack was abandoned and fluoroscopy utilized because of difficulty in threading the initial guidewire into the superior vena cava. CONCLUSION: The CathTrack electromagnetic locator system can be used to reliably position catheters for the establishment of long-term central venous access. Decreased cost and elimination of radiation exposure are distinct advantages of this system over fluoroscopy.

Traumatic renal artery dissection identified with dynamic helical computed tomography.

Intimal tears in the renal arteries typically result from traumatic mechanisms that produce rapid deceleration. These injuries usually progress to secondary thrombosis of the vessel. When the tear leads to dissection with luminal stenosis, early diagnosis and repair will preserve parenchymal function. Computed tomography has replaced intravenous pyelography as the radiographic study of choice for renal trauma. We present two patients with unilateral delay of renal contrast enhancement during dynamic helical computed tomography scan due to arterial stenosis from intimal dissection confirmed with arteriography. Both vessel injuries were successfully managed with endovascular stent placement. No previous description of this diagnostic strategy is reported in the literature.

Chlamydia pneumoniae in atherosclerotic carotid artery plaques: high prevalence among heavy smokers.

This study was designed to determine the prevalence of Chlamydia pneumoniae in carotid artery plaques. Although there have been numerous studies evaluating coronary plaques for this bacterium fewer studies have assessed noncoronary vasculature. In addition we wished to evaluate whether correlation exists between the presence of C. pneumoniae in carotid plaques and established risk factors for atherosclerosis. Sixty intact carotid artery plaques removed during surgery (carotid endarterectomy) were formalin-fixed and paraffin-embedded according to conventional techniques. These samples were evaluated by polymerase chain reaction analysis to detect presence of C. pneumoniae DNA. Results were tabulated and compared against established risk factors for atherosclerosis: diabetes, hypertension, hyperlipidemia, age, and smoking. Forty-two (70.0%) of the 60 plaques that were evaluated tested positive for the presence of C. pneumoniae DNA by polymerase chain reaction analysis. In the sample defined as being from heavy smokers (greater than 15-pack-year history) 33 (94.3%) of 35 plaques tested positive whereas two (5.7%) tested negative. This correlation demonstrated statistical significance (P = 1.36 x 10(-6), two-tailed Fisher exact test). Presence of C. pneumoniae in carotid plaques demonstrated no statistically significant correlation with diabetes, hypertension, or hyperlipidemia. Age as a risk factor was examined but not statistically evaluated because of the narrow range within our patient sample. Analysis of the data reveals that C. pneumoniae is present in large numbers of atheromatous plaques as is consistent with emerging data. What is interesting though is that 33 (94.3%) of the 35 smokers had plaques that tested positive for the bacterium as opposed to only nine (36.0%) of the 25 nonsmokers. Identification of specific populations exhibiting a high prevalence of C. pneumoniae may serve to focus future studies. Ongoing investigation will seek to determine whether C. pneumoniae plays an active role in the pathogenesis of atherosclerosis.