Transient obstruction of the mitral valve by a massive thrombus complicating percutaneous valvuloplasty.

Percutaneous transseptal mitral valvuloplasty was attempted in a patient with severe rheumatic mitral stenosis. Introduction of the balloon into the left atrium resulted in thrombotic occlusion of the mitral valve. Circulatory arrest ensued. The thrombus was disrupted during cardiopulmonary resuscitation. Thrombolysis was administered and the patient recovered uneventfully.

The pulmonary venous systolic flow pulse--its origin and relationship to left atrial pressure.

OBJECTIVES: The purpose of this study was to determine the origin of the pulmonary venous systolic flow pulse using wave-intensity analysis to separate forward- and backward-going waves. BACKGROUND: The mechanism of the pulmonary venous systolic flow pulse is unclear and could be a "suction effect" due to a fall in atrial pressure (backward-going wave) or a "pushing effect" due to forward-propagation of right ventricular (RV) pressure (forward-going wave). METHODS: In eight patients during coronary surgery, pulmonary venous flow (flow probe), velocity (microsensor) and pressure (micromanometer) were recorded. We calculated wave intensity (dP x dU) as change in pulmonary venous pressure (dP) times change in velocity (dU) at 5 ms intervals. When dP x dU > 0 there is a net forward-going wave and when dP x dU < 0 there is a net backward-going wave. RESULTS: Systolic pulmonary venous flow was biphasic. When flow accelerated in early systole (S1), pulmonary venous pressure was falling, and, therefore, dP x dU was negative, -0.6 +/- 0.2 (x +/- SE) W/m2, indicating a net backward-going wave. When flow accelerated in late systole (S2), pressure was rising, and, therefore, dP x dU was positive, 0.3 +/- 0.1 W/m2, indicating a net forward-going wave. CONCLUSIONS: Pulmonary venous flow acceleration in S1 was attributed to a net backward-going wave secondary to a fall in atrial pressure. However, flow acceleration in S2 was attributed to a net forward-going wave, consistent with propagation of the RV systolic pressure pulse across the lungs. Pulmonary vein systolic flow pattern, therefore, appears to be determined by right- as well as left-sided cardiac events.

Adverse events associated with balloon rupture during percutaneous coronary intervention.

BACKGROUND: Balloon rupture is a potential complication of coronary angioplasty. The literature is inconsistent regarding associated adverse consequences. The experience of St Paul's Hospital, University of British Columbia, Vancouver, British Columbia, with balloon rupture is reviewed. PATIENTS AND METHODS: All patients who underwent percutaneous coronary intervention complicated by balloon rupture at St Paul's Hospital from April 1992 to March 1996 were identified from the hospital's database (Seattle Systems, Seattle, Washington). Procedural logs, database records, clinical charts and all cineangiograms were reviewed in detail. RESULTS: A total of 2984 patients had percutaneous coronary revascularization and 110 patients experienced balloon rupture. These occurred in 101 (92%) native coronary arteries and 9 (8%) occurred in saphenous vein grafts. Stents were deployed in 44 (40%) patients; 34 of the stents used were half Johnson & Johnson PS153 stents (Johnson & Johnson Interventinal Systems, Peterborough, Ontario). An event-free postangioplasty course during the index hospitalization was observed in 102 patients (93%); eight patients (7%) had one or more important adverse events postprocedure. These included three deaths (one following a dissection and out-of-catheterization laboratory occlusion, a second following an abrupt occlusion of another target artery and emergency bypass surgery, and another with cardiogenic shock postmyocardial infarction and an unaltered course following angioplasty); one urgent bypass surgery after a left main dissection; and two nonfatal myocardial infarctions (one patient had tamponade and one patient experienced congestive heart failure). Four of the eight events were directly related to the procedure. The rate of death and emergency bypass surgery with balloon rupture did not differ from that of patients without balloon rupture in the authors' centre (1.8% versus 1.4%, not significant). CONCLUSIONS: The majority of patients did not experience any adverse clinical outcomes and demonstrated good angiographic results after balloon rupture. The data did not detect an excess of major adverse events beyond that expected in a diverse general angioplasty population.

Balloon entrapment during side-branch angioplasty through a stent.

Entrapment of the distal tip of a balloon catheter occurred during attempted passage between the struts of a stent into a side branch. Traction on the balloon resulted in fracture of the catheter shaft requiring extraction with percutaneous retrieval forceps.

Mechanisms, management, and outcome of failure of delivery of coronary stents.

In a single-center experience, initial failure of attempted stent delivery was relatively infrequent (2.7%) but was associated with increased need for urgent coronary bypass surgery. Delivery failure was more likely with coiled stents and dislodgment from the delivery balloon was more likely with hand-mounted or radiolucent stents.