Transvenous pacing lead-induced thrombosis: a series of cases with a review of the literature.

Although transvenous pacing is a safe treatment modality for bradyarrhythmias, serious thrombotic and embolic complications are reported to occur in 0.6-3.5% of cases. We describe 5 cases of pacemaker-associated thrombosis, 3 with a superior vena cava syndrome (SVC), 1 with an axillary vein thrombosis and 1 with a thrombus attached to the pacing lead in the right atrium. All of the patients were initially treated with intravenous heparin which proved successful as the sole treatment in only the least severe case (axillary vein thrombosis). One of the patients with SVC obstruction was successfully treated with intravenous heparin followed by thrombolytic therapy. The remaining 3 cases (2 SVC syndromes and 1 right atrial thrombus) required surgical removal of thrombus and pacing leads. Both of the patients with evidence of infection were in the group for whom failure of medical therapy necessitated surgery.

Characterization of Coxsackie B virus RNA in myocardium from patients with dilated cardiomyopathy by nucleotide sequencing of reverse transcription-nested polymerase chain reaction products.

This study was performed to detect and characterize the enterovirus present in myocardium of some patients with heart muscle disease by nucleotide sequencing of polymerase chain reaction (PCR) products after amplification with enterovirus group-specific primers. Enterovirus sequences have been detected previously in myocardium of patients with myocarditis or dilated cardiomyopathy and seem causal, although the particular virus serotypes involved have not been identified. In a prospective study of endomyocardial biopsy specimens from 35 consecutive patients with suspected heart muscle disease, enterovirus sequences from the 5' nontranslated region were amplified by reverse transcription-nested PCR using group-specific primers. This region contains both conserved and variable sequence motifs, characteristic of particular enterovirus serotypes. The nucleotide sequences of individual PCR products were determined by cycle sequencing and compared with all known sequences (GenBank/EMBOL), using the GCG software package. Endomyocardial biopsy specimens from 9 of 21 (42.9%) patients with a histologically confirmed diagnosis of dilated cardiomyopathy were positive for enterovirus by PCR, compared with only 1 of 14 (7.1%) patients with other myocardial pathological conditions (Fisher's exact probability=0.0275: odds ratio=9.75; 95% confidence interval=1.31-72.78). The nucleotide sequence of the PCR products differed, indicating no cross-contamination. However, computerized comparison showed that each had greatest homology with the 5' nontranslated region of Coxsackie B virus but contained up to 11% sequence variations compared with the prototype Coxsackie B3 strain Nancy. Parallel investigation of tissue from our mouse model of Coxsackievirus B3-induced myocarditis showed that nucleotide sequence changes are not introduced by reverse transcription or PCR. These data support the link between enteroviral infection and dilated heart muscle disease and suggest that Coxsackie B serotypes are the enteroviruses most frequently involved.

Atrial and pulmonary mass: intracardiac thrombus mimicking myxoma on multiplane transesophageal echocardiography.

Transesophageal echocardiography is the method of choice for investigating suspected intracardiac masses. It also plays a valuable role in the detection of central pulmonary artery embolism. We present a case that highlights the use of transesophageal echocardiography for imaging of a mass in the right atrium and the right pulmonary artery.

Comparison of clinical outcome after elective and "bail out" coronary stent insertion.

BACKGROUND: Coronary stents may be used electively during percutaneous transluminal coronary angioplasty (PTCA) or as a "bail-out" device to treat abrupt or threatened vessel closure following PTCA. OBJECTIVE: To compare the clinical outcome of elective and "bail-out" coronary stent insertion. DESIGN: A retrospective analysis of all patients receiving coronary stents. SETTING: Tertiary referral center performing over 400 PTCA procedures a year. PATIENTS: Fifty-six patients (42 male), mean age 57 (range = 32 to 78) years received 67 Palmaz-Schatz coronary stents. Forty-nine stents were deployed as "bail-out" in 41 patients (abrupt vessel closure in 15 and threatened vessel closure in 26) and 18 stents were deployed electively in 15 patients. MAIN OUTCOME MEASURES: Myocardial infarction, repeat angiography, coronary artery bypass graft surgery and death. RESULTS: Stents were successfully deployed in 56/62 (90.3%) patients. In-hospital events were significantly more common in the "bail-out" group compared to the elective group. The in-hospital events, comparing the "bail-out" group versus the elective group, were as follows: Death 2/41 (4.9%) vs 0/15 (0%), coronary artery bypass graft surgery (CABG) 8/41 (19.5%) vs 0/15 (0%), stent thrombosis 3/41 (7.3%) vs 0/15 (0%), and myocardial infarction 6/41 (14.6%) vs 1/15 (6.7%) respectively. After discharge no patient died or had CABG. One patient in the "bail-out" group had a myocardial infarct (late stent thrombosis). Two patients from each group had repeat angiography because of recurrent angina in the 6 month follow up period. CONCLUSION: "Bail-out" stenting has an increased incidence of in-hospital complications compared to elective procedures. If these short-term problems can be overcome however, the clinical events in the first 6 months after leaving hospital are low and similar to patients under-going elective procedures.

The value of transthoracic echocardiography during percutaneous balloon mitral valvuloplasty.

Percutaneous balloon mitral valvuloplasty is a standard alternative to surgery in a selected group of patients with symptomatic dominant rheumatic mitral stenosis. With careful transthoracic and transesophageal echocardiographic selection of patients, there is a low complication and high success rate. Echocardiography has also been established as extremely useful in the long-term follow-up of patients. We present four cases that highlight our view that transthoracic echocardiography should be performed during the procedure, after each balloon inflation, and before and after the intervention. In our experience transthoracic echocardiography during balloon mitral valvuloplasty is invaluable in assessing commissural separation, increasing mitral valve area, new mitral regurgitation, and occasional unexpected anatomic sequelae of balloon inflation.

In vitro evaluation of antimicrobial compounds for cysticidal activity against Acanthamoeba.

Amebic keratitis presents a therapeutic dilemma because Acanthamoeba, unlike Naegleria, encysts in infected tissues. To date, the results of medical therapy have been disappointing, and the optimal medical regimen for acanthamoeba keratitis is yet to be defined. Clinical cure necessitates eradication of the encysted amebae with medications known to have ocular toxic effects in combination with surgical maneuvers. Antiinfective agents possessing in vitro cysticidal activity include paromomycin, neomycin, ketoconazole, natamycin, and ciclopirox olamine, but no agent has been shown to be uniformly effective against all isolates of Acanthamoeba. Treatment of amebic cysts with propamidine isethionate plus either paromomycin or neomycin has produced slightly additive cysticidal effects. Multiple factors, including the varied clinical presentation and the lack of standardized in vitro techniques for the assay of cysticidal activity, account for the lack of correlation between in vitro activity and in vivo efficacy.

Rapid diagnosis of Acanthamoeba keratitis using calcofluor white.

Calcofluor white (CFW) is a chemofluorescent dye with an affinity for the polysaccharide polymers of amebic cysts. Using CFW staining with fluorescent microscopy, we demonstrated amebic cysts in corneal scrapings and keratectomy specimens from four patients with culture-proved Acanthamoeba keratitis and from one in whom CFW was the only positive laboratory test. Calcofluor white staining is simple, rapid, and highly reliable in the diagnosis of Acanthamoeba keratitis.

Conjunctival cytology of adult chlamydial conjunctivitis.

We assessed the diagnostic value of ocular cytologic examination by reviewing Giemsa-stained smears of conjunctival scrapings. Of 387 patients with a clinical diagnosis of adult chlamydial conjunctivitis, intracytoplasmic inclusions were found in 30 (8%). Both polymorphonuclear leukocytes and lymphocytes were common; the predominant cell type was not useful to differentiate chlamydial from adenoviral conjunctivitis. More sensitive cytologic features included the presence of plasma cells, Leber cells, blastoid cells, and multinucleated cells. Giemsa-stained conjunctival cytologic examination can provide a useful method to support the clinical diagnosis and to direct further laboratory testing.

Isolation, identification, and biological characterization of Acanthamoeba polyphaga from a human eye.

Trophozoites and cysts of an Acanthamoeba were repeatedly isolated from the corneal scrapings of a patient suffering from acute ulceration of the right eye. The ameba was cloned and cultivated axenically in a proteose peptone-yeast extract-glucose medium. At a later date the organism was identified as A. polyphaga on the basis of its morphologic characteristics, especially those of cysts. Experimental studies on the in vitro interaction of this organism with monkey kidney tissue culture (Vero line) and its pathogenicity to mice indicated that it was a low virulent strain. When large numbers of amebae (25,000+) were inoculated into Vero cell cultures, cytopathic effects (CPE) were noticed within 5 to 6 days. The CPE consisted of cell shrinkage, nuclear pyonosis, and discontinuity of cell sheet, and the cell culture was totally destroyed in 8 to 10 days. When 20,000+ amebae were instilled intranasally into each of 20 2-week-old mice, only 1 mouse died, on the 28th day. Amebae were isolated from the brain of the dead mouse, and trophozoites and cysts were also demonstrated in the brain sections. When amebae isolated from the brain were intranasally instilled into mice, they failed to kill the mice for at least 1 month; however, when 10,000+ amebae were inoculated intracerebrally, the mice died within 5 to 8 days, exhibiting symptoms of primary meningoencephalitis.