Ventricular Tachycardia in an Elderly Male With Brugada Syndrome.

We present a case of Brugada syndrome in a 74-year-old patient who presented with urine retention and incidentally found to have non-sustained ventricular tachycardia (NSVT) on electrocardiogram (ECG) and telemetry. To reveal characteristic type 1 Brugada pattern, right-pericardial lead was placed in the third right intercostal space. No antiarrhythmics were started, a loop recorder was implanted, and on follow-up episodes of self-terminating sustained ventricular tachycardia (VT) were noted. The patient was started on quinidine with resolution of VT.

Swallowing-induced atrial tachycardia: A rare demonstration on fluoroscopic esophagram.

BACKGROUND: Swallowing-associated arrhythmias are rare and most commonly present as atrial tachycardias. METHODS: We present a case of a 45-year-old female who experienced frequent episodes of palpitations and dyspnea occurring immediately after swallowing solid food. She was noted to have atrial tachycardia with deglutition that was recorded on the 12-lead electrocardiogram. She underwent fluoroscopic esophagram that demonstrated atrial tachycardia as the barium passed through the distal esophagus and gastroesophageal junction. CONCLUSION: Swallowing induced arrhythmias occur rarely and can be confirmed by EKG obtained during deglutition. Gastroesophageal evaluation is required to rule out primary esophageal disorders. Treatment of such arrhythmias is required if symptoms are intractable and can include pharmacotherapy and radiofrequency ablation.

Benign Metastasizing Leiomyoma Causing Severe Tricuspid Regurgitation and Heart Failure.

We present the case of a 51-year-old woman with severe tricuspid valve regurgitation due to aseptic tricuspid valve vegetation. She presented with bilateral lower extremity edema and a tricuspid valve vegetation was found on echocardiography. Initially, infectious and autoimmune causes of valve vegetation were considered; however, on biopsy, the mass was ultimately found to be a benign metastasizing leiomyoma (BML). Additional history revealed clinical features consistent with uterine leiomyomas, which metastasized to all leaflets the tricuspid valve, causing symptoms of heart failure. Benign metastasizing leiomyoma is rare itself, but when found, typically presents as asymptomatic pulmonary nodules. Mechanism of spread is unknown. Diagnosis is typically made long after a hysterectomy or fibroidectomy, but in our case, the BML was found prior to an actual fibroid diagnosis. By comparison, metastasis to the heart is extremely rare and has a higher potential for morbidity. Our patient required open heart surgery and tricuspid valve replacement for management of her symptoms, but her risk of further or recurrent metastasis going forward is unknown. Management strategy to prevent metastases in such cases of aggressive disease is not an established protocol and needs to be further studied.

Beta-blockers for chest pain associated with recent cocaine use.

BACKGROUND: Although beta-blockers prevent adverse events after myocardial infarction, they are contraindicated when chest pain is associated with recent cocaine use. Recommendations against this use of beta-blockers are based on animal studies, small human experiments, and anecdote. We sought to test the hypothesis that beta-blockers are safe in this setting. METHODS: We performed a retrospective cohort study of consecutive patients admitted to the San Francisco General Hospital, San Francisco, California, with chest pain and urine toxicologic test results positive for cocaine, from January 2001 to December 2006. Mortality data were collected from the National Death Index. RESULTS: Of 331 patients with chest pain in the setting of recent cocaine use, 151 (46%) received a beta-blocker in the emergency department. There were no meaningful differences in electrocardiographic changes, troponin levels, length of stay, use of vasopressor agents, intubation, ventricular tachycardia or ventricular fibrillation, or death between those who did and did not receive a beta-blocker. After adjusting for potential confounders, systolic blood pressure significantly decreased a mean 8.6 mm Hg (95% confidence interval, 14.7-2.5 mm Hg) in those receiving a beta-blocker in the emergency department compared with those who received their first beta-blocker in the hospital ward (P = .006). Over a median follow-up of 972 days (interquartile range, 555-1490 days), after adjusting for potential confounders, patients discharged on a beta-blocker regimen exhibited a significant reduction in cardiovascular death (hazard ratio, 0.29; 95% confidence interval, 0.09-0.98) (P = .047). CONCLUSION: beta-Blockers do not appear to be associated with adverse events in patients with chest pain with recent cocaine use.

Intradiscal thermal therapy using interstitial ultrasound: an in vivo investigation in ovine cervical spine.

STUDY DESIGN: In vivo investigation of intradiscal ultrasound thermal therapy in ovine cervical spine model. OBJECTIVE: To evaluate the potential of interstitial ultrasound for selective heating of intradiscal tissue in vivo. SUMMARY OF BACKGROUND DATA: Application of heat in the spine using resistive wire and radiofrequency current heating devices is currently being used clinically for minimally invasive treatment of discogenic low back pain. Treatment temperatures are representative of those required for thermal necrosis of ingrowing nociceptor nerve fibers and disc cellularity alone, or with coagulation and restructuring of anular collagen in the high temperature case. METHODS: Two interstitial ultrasound applicator design configurations with directional heating patterns were evaluated in vivo in ovine cervical intervertebral discs (n = 62), with up to 45-day survival periods. Two heating protocols were employed in which the temperature measured 5 mm away from the applicator was controlled to either <54 C (capable of nerve and cellular necrosis) or >70 C (for coagulation of collagen) for a 10-minute treatment period. Transient and steady state temperature maps, calculated thermal doses (t43), and histology were used to assess the thermal treatments. RESULTS: These studies demonstrated the capability to control spatial temperature distributions within selected regions of the in vivo intervertebral disc and anular wall using interstitial ultrasound. CONCLUSIONS: Ultrasound energy is capable of penetrating within the highly attenuating disc tissue to produce more extensive radial thermal penetration, lower maximum intradiscal temperature, and shorter treatment times than can be achieved with current clinical intradiscal heating technology. Thus, interstitial ultrasound offers potential as a more precise and faster heating modality for the clinical management of low back pain and studies of thermal effects on disc tissue in animal models.

Intradiscal thermal therapy does not stimulate biologic remodeling in an in vivo sheep model.

STUDY DESIGN: Thermal energy was delivered in vivo to ovine cervical discs and the postheating response was monitored over time. OBJECTIVES: To determine the effects of two distinctly different thermal exposures on biologic remodeling: a "high-dose" regimen intended to produce both cellular necrosis and collagen denaturation and a "low-dose" regimen intended only to kill cells. SUMMARY OF BACKGROUND DATA: Thermal therapy is a minimally invasive technique that may ameliorate discogenic back pain. Potential therapeutic mechanisms include shrinkage of collagenous tissues, stimulation of biologic remodeling, and ablation of cytokine-producing cells and nociceptive fibers. METHODS: Intradiscal heating was performed using directional interstitial ultrasound applicators. Temperature and thermal dose distributions were characterized. The effects of high (>70 C, 10 minutes) and low (52 C-54 C, 10 minutes) temperature treatments on chronic biomechanical and architectural changes were compared with sham-treated and control discs at 7, 45, and 180 days. RESULTS: The high-dose treatment caused both an acute and chronic loss of proteoglycan staining and a degradation of biomechanical properties compared with low-dose and sham groups. Similar amounts of degradation were observed in the low-dose and sham-treated discs relative to the control discs at 180 days after treatment. CONCLUSIONS: While a high temperature thermal protocol had a detrimental effect on the disc, the effects of low temperature treatment were relatively minor. Thermal therapy did not stimulate significant biologic remodeling. Future studies should focus on the effects of low-dose therapy on tissue innervation and pro-inflammatory factor production.

Feasibility of using interstitial ultrasound for intradiscal thermal therapy: a study in human cadaver lumbar discs.

Application of heat in the spine using resistive wire heating devices is currently being used clinically for minimally invasive treatment of discogenic low back pain. In this study, interstitial ultrasound was evaluated for the potential to heat intradiscal tissue more precisely by directing energy towards the posterior annular wall while avoiding vertebral bodies. Two single-element directional applicator design configurations were tested: a 1.5 mm OD direct-coupled (DC) applicator which can be implanted directly within the disc, and a catheter-cooled (CC) applicator which is inserted in a 2.4 mm OD catheter with integrated water cooling and implanted within the disc. The transducers were sectored to produce 90 degrees spatial heating patterns for directional control. Both applicator configurations were evaluated in four human cadaver lumbar disc motion segments. Two heating protocols were employed in this study in which the temperature measured 5 mm away from the applicator was controlled to either T=52 degrees C, or T>70 degrees C for the treatment period. These temperatures (thermal doses) are representative of those required for thermal necrosis of in-growing nociceptor nerve fibres and disc cellularity alone, or with coagulation and restructuring of annular collagen in the high-temperature case. Steady-state temperature maps, and thermal doses (t43) were used to assess the thermal treatments. Results from these studies demonstrated the capability of controlling temperature distributions within selected regions of the disc and annular wall using interstitial ultrasound, with minimal vertebral end-plate heating. While directional heating was demonstrated with both applicator designs, the CC configuration had greater directional heating capabilities and offered better temperature control than the DC configuration, particularly during the high-temperature protocol. Further, ultrasound energy was capable of penetrating within the highly attenuating disc tissue to produce more extensive radial thermal penetration, lower maximum intradiscal temperature, and shorter treatment times than can be achieved with current clinical intradiscal heating technology. Thus, interstitial ultrasound offers potential as a more precise and faster heating modality for the clinical management of low back pain.