Glossopharyngeal insufflation and pulmonary hemodynamics in elite breath hold divers.

PURPOSE: Acute voluntary lung hyperinflation provoked by glossopharyngeal insufflation (GI) elicits numerous, possibly deleterious, effects on the cardiopulmonary system by increasing intrathoracic pressures far above normal values. This study quantifies acute pulmonary hemodynamics during GI using phase-contrast magnetic resonance imaging (MRI). METHODS: Hemodynamic parameters were measured in nine elite male breath hold divers with a mean age of 30 yr (range = 20-43 yr) by velocity-encoding cine (VEC)-MRI of the main pulmonary artery (PA) before, during, and after GI. Simultaneously, GI-lung volume (GIVEC-MRI) was measured by MR-compatible spirometry. RESULTS: Hemodynamic parameters were associated with GIVEC-MRI. Highly significant changes during GI were shown for the mean flow in the PA, which decreased by 45% (P < 0.007), and right ventricular output and cardiac index, which decreased by 41% and 40%, respectively (P < 0.007). Acceleration time also decreased highly significant by 36% during GI (P < 0.007). All hemodynamic parameters except acceleration time returned to baseline after GI. CONCLUSIONS: Acute voluntary lung hyperinflation mimics changes seen in pulmonary arterial hypertension, but unlike the latter, these changes are fully reversible shortly after cessation of voluntary lung hyperinflation. Persistent changes due to repetitive GI could not be detected.

Delayed enhancement magnetic resonance imaging is a significant prognostic factor in patients with non-ischemic cardiomyopathy.

BACKGROUND: Delayed enhancement (DE) on cardiac magnetic resonance imaging (CMR) is a marker of myocardial fibrosis. The absence of DE in CMR is a predictor of left ventricular (LV) functional improvement in patients with non-ischemic cardiomyopathy (NICM), so in the present study it was investigated whether presence of DE has prognostic significance in patients with NICM at long-term follow-up. METHODS AND RESULTS: The 79 patients (56.4+/-13.5 years, 48 males) with NICM (LV ejection fraction <35%, no significant coronary artery disease) were monitored for occurrence of cardiac events. CMR was performed to assess DE. Cardiac events were defined as rehospitalization (because of worsening of heart failure), cardiac transplantation or death. There were 37 patients without and 42 patients with DE. The mean follow-up duration was 19+/-10 months. There was 1 event (2.7%, 1 rehospitalization) in the DE (-) group, whereas 13 events (30.9%, 1 death, 1 transplantation, 11 rehospitalizations) occurred in the DE (+) group. The event-free survival was significantly longer in the DE (-) group than in the DE (+) group (38.9+/-1.0 vs 28.4+/-2.7 months, P<0.01). Multivariate regression analysis revealed that presence of DE was the most potent, independent predictor of cardiac events (hazard ratio 8.06, confidence interval 1.03+/-63.41, P<0.05). CONCLUSIONS: The presence of DE in CMR is a significant predictor of future cardiac events in patients with NICM.

Quantification of regional calcium burden in chronic total occlusion by 64-slice multi-detector computed tomography and procedural outcomes of percutaneous coronary intervention.

BACKGROUND: One of the most important reasons for failure of percutaneous coronary intervention (PCI) in chronic total occlusion (CTO) is calcified plaque, which either prevents passage of guide wire or ruptures after balloon inflation. We sought to evaluate whether quantified calcium contents of CTO on multi-detector computed tomography (MDCT) correlate with immediate procedural outcomes. METHODS: Sixty-four patients with 72 CTO lesions who underwent 64-slice MDCT prior to PCI were investigated. The lesions were divided into 2 groups according to procedural outcomes (55 lesions with PCI-success group, 17 lesions with PCI-failure group). Clinical, angiographic and MDCT parameters, including regional calcium volume (RCaV), regional calcium score (RCaS), regional calcium equivalent mass (RCaEq), and relative calcium area at the most calcified cross section of CTO (%CaS/CSA), were compared between the two groups. RESULTS: The duration of CTO was shorter in PCI-success group than PCI-failure group (7.16 ± 10.5 vs 15.59 ± 14.92 months, p=0.011), and the procedural success rate was 76.3%. Regional calcium-related parameters (RCaV 52.86 ± 58.39 vs 7.26 ± 15.27 mm(3), p<0.001; RCaS 72.71 ± 78.4 vs 9.66 ± 20.2, p<0.001; RCaEq 12.58 ± 12.97 vs 1.84 ± 3.716 mgCaHA, p<0.001; %CaS/CSA 53.9 ± 20.3 vs 30.4 ± 17.1%, p=0.009) in the occluded segment were higher and the occlusion length was longer (37.44 ± 27.48 vs 22.00 ± 18.04 mm, p<0.021) in PCI-failure group compared to PCI-success group. Multivariate regression analysis showed that only %CaS/CSA was a significant determinant of PCI-failure. CONCLUSIONS: Precise quantification of regional calcification and measurement of the occluded segment by high resolution MDCT can deliver important information for predicting procedural outcomes in PCI of CTO.

Delayed hyperenhancement magnetic resonance imaging is useful in predicting functional recovery of nonischemic left ventricular systolic dysfunction.

BACKGROUND: About 25% of the patients with nonischemic left ventricular (LV) systolic dysfunction improve spontaneously. However, the predictors for functional improvement are not known. We hypothesized that myocardial fibrosis, assessed by cardiac magnetic resonance (CMR) imaging, may predict the reversibility of nonischemic LV systolic dysfunction. METHODS AND RESULTS: CMR was performed in 46 patients. Baseline and follow-up echocardiography was performed to assess the recovery of LV function. There were 24 patients with absence of delayed hyperenhancement (group 1) and 22 patients with delayed hyperenhancement (group 2). There were significant difference for the follow-up LV end-diastolic dimension (56.2 +/- 7.3 versus 62.6 +/- 11.9), LV end-systolic dimension (43.2 +/- 9.2 versus 52.8 +/- 12.6), and LV ejection fraction (LVEF) (46.8 +/- 12.4% versus 31.6 +/- 11.3%). Follow-up echocardiography of 19/24 (79.2%) patients in group 1 showed functional recovery, whereas only 2/22 (9.1%) patient in group 2 showed functional recovery. The absence of delayed hyperenhancement was associated with sensitivity, specificity, positive predictive value, and negative predictive value of 90.5%, 79.2%, 80.0%, and 90.9%, respectively. CONCLUSION: Absence of delayed hyperenhancement demonstrated excellent sensitivity and negative predictive value in predicting functional recovery of nonischemic LV systolic dysfunction.