Guide wire-induced coronary artery spasm during percutaneous transluminal coronary angioplasty. A case report

Microbubble formulation influences inflammatory response to focused ultrasound exposure in the brain

Focused ultrasound and microbubble (FUS + MB)-mediated blood-brain barrier (BBB) permeability enhancement can facilitate targeted brain-drug delivery. While controlling the magnitude of BBB permeability enhancement is necessary to limit tissue damage, little work has attempted to decouple these concepts. This work investigated the relationship between BBB permeability enhancement and the relative transcription of inflammatory mediators 4 h following sonication. Three microbubble formulations, Definity, BG8774, and MSB4, were compared, with the dose of each formulation normalized to gas volume. While changes in the transcription of key proinflammatory mediators, such as Il1b, Ccl2, and Tnf, were correlated to the magnitude of BBB permeability enhancement, these correlations were not independent of microbubble formulation; microbubble size distribution may play an important role, as linear regression analyses of BBB permeability magnitude versus differential gene expression for these proinflammatory mediators revealed significantly greater slopes for MSB4, a monodisperse microbubble with mean diameter of 4 μm, compared to Definity or BG8774, both polydisperse microbubbles with mean diameters below 2 μm. Additionally, the function of an acoustic feedback control algorithm, based on the detection threshold of ultraharmonic emissions, was assessed. While this control strategy was effective in limiting both wideband emissions and red blood cell extravasation, microbubble formulation was found to influence the magnitude of BBB leakage and correlations to acoustic emissions. This work demonstrates that while the initial magnitude of FUS + MB-mediated BBB permeability enhancement has a clear influence on the subsequent inflammatory responses, microbubble characteristics influence these relationships and must also be considered.

Differential diagnosis of non-atherosclerotic left main coronary artery stenosis

A left main coronary artery (LMCA) stenosis without any atherosclerotic changes elsewhere in the coronary artery tree is a rare finding, and some uncommon reasons for luminal narrowing should be considered. An unusual case of non-atherosclerotic LMCA stenosis is reported.A middle-aged patient presented with acute myocardial infarction. An immediate coronary angiography was ordered and revealed a subtotal mid LMCA stenosis. A drug-eluting stent was successfully implanted in the LMCA.Operative revascularisation was recommended. Routine surgery was performed and surprisingly revealed an extended mass of a mediastinal tumour surrounding the aortic root. Histopathological examination of the tumour revealed a poorly differentiated squamous cell carcinoma.Postoperatively, the patient was treated with chemotherapy (carboplatin and docetaxel). Five years after the first admission to our hospital, the patient died as a result of ventricular fibrillation.The differential diagnosis of non-atherosclerotic LMCA stenoses is discussed.

Aborted sudden cardiac death in a 52-yearold man without structural heart disease

Sudden cardiac death in the absence of apparent structural heart disease is an uncommon phenomenon. The majority of these patients do not have 'normal' hearts and specific diagnostic tools are required to identify structural or functional abnormalities. We describe the history of a 50-yearold man who survived ventricular fibrillation. Clinical investigation, including a coronary angiography and electrophysiological study, appeared to be normal. An implantable cardioverter defibrillator was inserted. Follow-up Holter monitoring was performed after a recurrent episode of ventricular tachycardia. It demonstrated transient ST-segment elevation. An acetylcholine provocation test was subsequently carried out. Reversible coronary spasm of the left descending coronary artery was found, during which a diagonal branch was occluded. It may be concluded that coronary spasm provocation is of value in the routine diagnostic work-up of patients surviving sudden cardiac death without apparent heart disease. (Neth Heart J 2008;16:239-41.).

Multiphoton imaging of ultrasound/Optison mediated cerebrovascular effects in vivo

Ultrasound (US) enhanced with microbubble contrast agents may transiently disrupt the blood-brain barrier (BBB) with minimal damage, providing a technique for noninvasive, localized drug-delivery deep within the brain. The mechanism and temporal profile of disruption are not understood, owing to the limitations of imaging modalities used previously. In this study, we monitored US-induced BBB disruption with multiphoton microscopy, providing high-resolution temporal and spatial information about the permeabilization mechanism and immediate effects of US exposure. Anesthetized C57 mice were prepared with a craniotomy and injected intravenously with fluorescent dyes to permit visualization of the vasculature and BBB integrity. The animals were imaged through a cranial window while exposed to low-intensity US (f=1.029 MHz, power=0.2 W) with a coincident intravenous injection of Optison (a microbubble contrast agent). We observed arteriolar vasoconstriction on US exposure that disrupted blood flow and lasted up to 5 mins; BBB disruption occurred via two characteristically distinct processes-perivascular fluorescence gradually increased (over minutes) along the length of the affected vessel without apparent rupture of the vessel wall or rapidly (seconds) increased in select, focal regions. These data corroborated previous studies suggesting increased endothelial transcytosis and breached tight junctions and demonstrated vasoconstriction, which might alter BBB permeability by modifying cerebral blood flow.

When one won't do it, use two—double “Buddy” wiring to facilitate stent advancement across a highly calcified artery

Percutaneous coronary intervention (PCI) of heavily calcified vessels poses several problems including difficulty in delivering stents to the target lesion. Effective strategies include rotational atherectomy and the use of a "buddy" wire, the latter acting as a track that directs the stent away from the vessel wall. There are no reports in the literature of using a second "buddy" wire when one fails. We report on a case of a second "buddy" wire saving the day during PCI of a highly calcified right coronary artery wherein the stent failed to reach the lesion until the second wire was deployed.

Safety of intracoronary Doppler flow measurement

BACKGROUND

With the introduction of Doppler-tipped guide wires, intracoronary Doppler flow measurement has been increasingly accepted as an additional diagnostic approach in the catheterization laboratory. However, the safety of intracoronary Doppler flow measurement has not been well-investigated. The purpose of our study was to evaluate the safety of intracoronary Doppler flow measurement using the Doppler FloWire (Cardiometrics, Mountain View, Calif).

METHODS AND RESULTS

A total of 906 patients were examined by intracoronary Doppler with a 0.014-inch or an 0.018-inch Doppler FloWire. For coronary flow reserve measurement, intracoronary injection of adenosine or papaverine was used. Of the patients studied, 77 were cardiac transplant recipients and 829 were patients who had not received a transplant, of whom 617 had undergone diagnostic coronary procedures and 212 had coronary interventions. In 27 (2.98%) of 906 patients adverse cardiac events were observed. Fifteen (1.66%) of 906 patients had severe transient bradycardia develop (asystole or second- to third-degree atrioventricular block) after intracoronary administration of adenosine, 14 of which occurred in the right coronary artery and 1 in the left anterior descending artery. Nine (0.99%) of 906 patients had coronary spasm during the passage of the Doppler wire (5 in the right coronary artery, 4 in the left anterior descending artery). Two (0.22%) of 906 patients had ventricular fibrillation during the procedure. Hypotension with bradycardia and ventricular extrasystole each occurred in 1 (0.11%) of 906 patients. The incidence of complication was significantly higher in transplant recipients than in patients who underwent either diagnostic or interventional procedures (12.99% vs 2.43% vs 0.94%, P <.001). The Doppler measurements in the right coronary artery were associated with a higher incidence of complications, especially bradycardia, compared with the left anterior descending and the left circumflex arteries (right coronary, 5.87% vs left anterior descending, 1.05% vs left circumflex, 0.17%; P <.001). All complications were cured medically.

CONCLUSION

Intracoronary Doppler flow measurement with Doppler wires and intracoronary administration of adenosine is a safe method. However, severe complications such as bradycardia and coronary spasm can occur. Attention should be paid to the examination of the right coronary artery, especially in heart transplant recipients.

Severe spasm of a radial artery coronary bypass graft during coronary intervention

Coronary spasm is a well-recognized observation during coronary angiography. This report describes a patient who developed spasm of a radial artery bypass graft during coronary intervention. There are many reports on the angiographic follow-up to confirm the surgical results for patency in radial arterial conduits. We share our experience with this first case in the literature noted to have severe vasospasm during PTCA. Cathet. Cardiovasc. Intervent. 47:331-335, 1999.