Clinical significance of right ventricular dilatation in patients with right ventricular infarction

Proximal complete occlusion of right coronary artery presenting with precordial ST-segment elevation: A case report

BACKGROUND

It is well known that cardiologists empirically judge the culprit lesion of acute ST-segment elevation myocardial infarction (STEMI) according to the corresponding electrocardiographic leads. However, In addition to the obstruction of left anterior descending (LAD) coronary artery, rare cases with the occlusion of proximal right coronary artery (RCA) and/or isolated right ventricular (RV) branch showed the ST-segment elevation in precordial leads V1-V3 as well.

CASE SUMMARY

We reported a patient complaining of acute chest pain and suffering ventricular fibrillation (VF) on admission. The electrocardiogram (ECG) showed mild ST-segment elevation in precordial leads V1-V3 and V4R. Bedside echocardiography displayed normal left ventricular ejection fraction and slight RV dilation. Proximal occlusion of nondominant RCA was confirmed by coronary angiography and urgent percutaneous coronary intervention (PCI) to RCA successfully resolved the chest pain and ST-segment elevation.

CONCLUSION

Undoubtedly, coronary angiography is usually the definite measurement for the diagnosis of culprit lesion. However, bedside echocardiography, ST-segment features in left and right precordial leads, and heart rate will be the additional information for judging ST-segment elevation in precordial leads V1-V3 resulting from occlusion of RCA or LAD.

Quantitation of Right Ventricular Volumes and Ejection Fraction by Three-Dimensional Echocardiography in Patients: Comparison with Magnetic Resonance Imaging and Radionuclide Ventriculography

Three-dimensional echocardiography (3DE) provides volumetric measurements without geometric assumptions. Volume-rendered 3DE has been shown to be accurate for the measurement of right ventricular (RV) volumes in vitro and in animal studies; however, few data are available regarding its accuracy in patients. This study examined the accuracy of 3DE for quantitation of RV volumes and ejection fraction (EF) in patients, compared to magnetic resonance imaging (MRI) and radionuclide ventriculography (RNV). Twenty patients underwent MRI, gated equilibrium RNV, and 3DE using rotational acquisition from both the transesophageal and transthoracic approaches. RV volumes and EF were calculated from the 3DE data using multislice analysis (true Simpson's rule). RV volumes calculated by MRI (end-diastolic volume (EDV) 109.4 +/- 34.3 mls, end-systolic volume (ESV) 59.6 +/- 31.0 mls, and EF 47.7 +/- 17.1%) agreed closely with 3DE. For transesophageal echocardiography, EDV was 108.1 +/- 29.7 mls (r = 0.86, mean difference 1.3 +/- 17.8 mls); ESV was 62.5 +/- 23.8 mls (r = 0.85, mean difference 2.8 +/- 15.1 mls); and EF was 43.2 +/- 11.7% (r = 0.84, mean difference 4.5 +/- 9.7%). For transthoracic echocardiography, EDV was 107.7 +/- 27.5 mls (r = 0.85, mean difference 1.6 +/- 18.2 mls); ESV was 59.7 +/- 22.1 mls (r = 0.93, mean difference 3.2 +/- 19.6 mls); and EF was 45.2 +/- 11.5% (r = 0.86, mean difference 2.0 +/- 9.4%). There were close correlations, small mean differences and narrow limits of agreement between RNV-derived EF (43.4 +/- 12.1%) and both transesophageal (r = 0.95 mean difference 0.2 +/- 3.7%) and transthoracic 3DE (r = 0.95, mean difference 1.8 +/- 5.4%). Three-dimensional echocardiography is a promising new method of calculating RV volumes and EF, comparing well with MRI and RNV. The accuracy of transthoracic 3DE was comparable to that of the transesophageal approach. Three-dimensional echocardiography has the potential to be useful in the clinical assessment of RV disorders.

Long term complications in single and dual chamber pacing are influenced by surgical experience and patient morbidity

OBJECTIVE

To determine how short and long term complication rates after pacemaker implantation are influenced by patient morbidity, operator experience, and choice of pacing system.

DESIGN

Retrospective analysis of 1884 patients who received VVI (n = 610), VDD (n = 371), or DDD devices (n = 903) between 1990 and 2001. Follow up period was 64 (34) months. The influence of age, sex, coronary artery disease, myocardial infarction, reduced left ventricular (LV) function, right ventricular (RV) dilatation, atrial fibrillation, device type, and operator experience on operation time and complication rate were analysed.

RESULTS

Operation time was prolonged in patients with coronary artery disease, inferior myocardial infarction, reduced LV function, and RV dilatation. Implantation of DDD pacemakers prolonged operation time, particularly among operators with a low or medium level of experience. The overall complication rate was 4.5%. Sixty seven per cent of these complications occurred within the first three months. Complication rate was increased by age, reduced LV function, and RV dilatation. Implantation of DDD systems led to a higher complication rate (6.3%) than implantation of VVI (2.6%) or VDD pacemakers (3.2%). These differences were present only among operators with a low or medium level of experience.

CONCLUSIONS

Operation time and complication rate increased with age, impaired LV function, and RV dilatation. Complication rates were higher with DDD than with VVI or VDD implantation and were excessive among inexperienced but not experienced operators.

Myocardial Performance Index in Evaluation of Acute Right Ventricular Myocardial Infarction

The goal of this study was to evaluate the role of Doppler time interval-derived myocardial performance index (MPI) in the setting of acute right ventricular myocardial infarction (RVMI). Inferior myocardial infarction is accompanied by RVMI in over a third of cases. We do not have easily applicable noninvasive tools for reliably quantifying the right ventricular (RV) dysfunction in RVMI and to serially follow alterations. Clinical and echocardiography data of all acute inferior myocardial infarction (IMI) admissions (n = 135) to our referral teaching institute were prospectively collected for the study. After exclusions, study group comprised of 36 patients with RVMI diagnosed by >/=1 mm ST segment elevation in V3R-V5R of right-sided ECG and 63 patients without RVMI constituted the control group. All patients underwent echocardiography within 24 hours of admission. Normal range of MPI for our laboratory was estimated from 50 age-matched healthy subjects. RV MPI was elevated to a mean of 0.53 +/- 0.22 in RVMI (Normal MPI 0.20 +/- 0.05, P-value < 0.001). IMI without RVMI did not elevate MPI significantly (0.21 +/- 0.17, P-value NS). Repeat MPI estimation in 11 RVMI (7 thrombolyzed) patients after 5 days showed dramatic reduction (0.23 +/- 0.12, P-value < 0.001). This reduction was noted irrespective of thrombolysis. RV MPI >/= 0.30 has high sensitivity (82%) and specificity (95%) for the diagnosis of RVMI in the presence of acute IMI. MPI can reliably diagnose RV infarction. It can be used to quantify right ventricular dysfunction and assess acute improvements in RV function.

Prognostic significance of precordial ST-segment changes in acute inferior wall myocardial infarction

STUDY OBJECTIVE

To examine the clinical significance of precordial ST-segment changes in patients with acute Q-wave inferior wall myocardial infarction.

DESIGN

Prospective evaluation (clinical follow-up) of Q-wave inferior wall myocardial infarction over a 6-year period in patients who fulfilled the inclusion criteria.

SETTING

Coronary care unit at a university hospital.

PATIENTS

Two hundred consecutive patients with acute Q-wave inferior wall myocardial infarction admitted to the coronary care unit within 24 h from the onset of chest pain.

MEASUREMENTS AND RESULTS

Precordial ST-segment depression resolved <24 h (transient) after admission in 84 patients, lasted > or = 24 h (persistent) in 48 patients, and was absent in 68 patients, while ST-segment elevation in V4R was detected in 60 patients. Seventy-one patients had major in-hospital complications and 18 patients died in the hospital. When nine variables were used in the multivariate analysis, right ventricular dilatation and persistent precordial ST-segment depression were the important factors related to major in-hospital complications, whereas age, alveolar arterial oxygen difference, and persistent precordial ST-segment depression were important for in-hospital deaths.

CONCLUSION

Left ventricular posterior wall involvement, diagnosed by persistent precordial ST-depression, was an independent and stronger predictor of major in-hospital complications and deaths than right ventricular involvement in patients with acute Q-wave inferior wall myocardial infarction.