Prognostic significance of complete atrioventricular block in patients with acute inferior myocardial infarction with and without right ventricular involvement

Inferior wall myocardial infarction occurs in approximately 50% of all myocardial infarctions. The most common conduction disorder of this disease is complete atrioventricular block. Immediate attention must be given to the myocardial infarction patients with conduction block due to the increased mortality rate in these patients. Temporary pacemaker implantation and permanent pacemaker implantation are recommended in complete atrioventricular block cases that do not improve with reperfusion. In this case report, a 64-year-old-female patient came to the emergency department of a rural General Hospital with complaints of epigastric pain, dizziness, nausea, and vomiting for 2 days before admission. She had uncontrolled hypertension without a history of diabetes mellitus, dyslipidemia, smoking, or a family history of heart disease. The electrocardiogram displayed an acute inferior wall myocardial infarction and complete atrioventricular block with escape junctional rhythm with a heart rate of 17 bpm. She was diagnosed with nonreperfused inferior wall myocardial infarction and a complete atrioventricular block. She was successfully treated with only dopamine and epinephrine as the definitive treatment because the patient refused to be referred to a tertiary hospital for percutaneous coronary intervention and pacemaker implantation due to financial reasons. Dopamine and epinephrine may be considered for complete atrioventricular block if transfer to a higher level of care is not feasible and as bridge therapy while waiting for transfer.

Download Full-text

Right coronary artery ligation in mice: a novel method to investigate right ventricular dysfunction and biventricular interaction

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00573.2018 ◽

2019 ◽

Vol 316 (3) ◽

pp. H684-H692 ◽

Cited By ~ 1

Author(s):

Pierre Sicard ◽

Timothée Jouitteau ◽

Thales Andrade-Martins ◽

Abdallah Massad ◽

Glaucy Rodrigues de Araujo ◽

...

Keyword(s):

Myocardial Infarction ◽

Coronary Artery ◽

Infarct Size ◽

Right Ventricular ◽

Right Coronary Artery ◽

Ventricular Dysfunction ◽

Left Ventricular ◽

Coronary Artery Ligation ◽

Inferior Myocardial Infarction ◽

Acute Inferior Myocardial Infarction

Right ventricular (RV) dysfunction can lead to complications after acute inferior myocardial infarction (MI). However, it is unclear how RV failure after MI contributes to left-sided dysfunction. The aim of the present study was to investigate the consequences of right coronary artery (RCA) ligation in mice. RCA ligation was performed in C57BL/6JRj mice ( n = 38). The cardiac phenotypes were characterized using high-resolution echocardiography performed up to 4 wk post-RCA ligation. Infarct size was measured using 2,3,5-triphenyltetrazolium chloride staining 24 h post-RCA ligation, and the extent of the fibrotic area was determined 4 wk after MI. RV dysfunction was confirmed 24 h post-RCA ligation by a decrease in the tricuspid annular plane systolic excursion ( P < 0.001) and RV longitudinal strain analysis ( P < 0.001). Infarct size measured ex vivo represented 45.1 ± 9.1% of the RV free wall. RCA permanent ligation increased the RV-to-left ventricular (LV) area ratio ( P < 0.01). Septum hypertrophy ( P < 0.01) was associated with diastolic septal flattening. During the 4-wk post-RCA ligation, LV ejection fraction was preserved, yet it was associated with impaired LV diastolic parameters ( E/ E′, global strain rate during early diastole). Histological staining after 4 wk confirmed the remodeling process with a thin and fibrotic RV. This study validates that RCA ligation in mice is feasible and induces RV heart failure associated with the development of LV diastolic dysfunction. Our model offers a new opportunity to study mechanisms and treatments of RV/LV dysfunction after MI. NEW & NOTEWORTHY Right ventricular (RV) dysfunction frequently causes complications after acute inferior myocardial infarction. How RV failure contributes to left-sided dysfunction is elusive because of the lack of models to study molecular mechanisms. Here, we created a new model of myocardial infarction by permanently tying the right coronary artery in mice. This model offers a new opportunity to unravel mechanisms underlying RV/left ventricular dysfunction and evaluate drug therapy.

Download Full-text