Isolated Right Ventricular Infarction: A Case Report and Literature Review

Isolated right ventricular (RV) infarction is extremely rare and its diagnosis may be challenging, because RV infarction most often occurs simultaneously with infarction of the inferior wall of the left ventricle. A 66-year-old man with a history of diabetes mellitus presented with cold sweat and general malaise. Although his symptoms were atypical for myocardial infarction, he was quickly diagnosed with RV infarction and successfully underwent urgent percutaneous coronary intervention. He was definitely diagnosed with isolated RV infarction by a scintigram and cardiac magnetic resonance imaging. Our review showed the importance of the combined assessment in the diagnosis of isolated RV infarction.     

Severe Right Ventricular Dysplasia with Absent Pulmonary Valve Syndrome and Tricuspid Atresia: A Literature Review

This is a newborn male prenatally diagnosed with severe right ventricular (RV) hypertrophy and depressed function, aneurysmal dilation of the main pulmonary artery and tachyarrhythmia. Postnatally, he required immediate intubation and inotropic support. Echocardiogram revealed a large dysplastic RV, absent pulmonary valve syndrome (APVS), markedly dilated pulmonary arteries and tricuspid atresia (TA). The trabecular portion of the RV was excessively trabeculated and severely dilated. Inflow and infundibular walls were thin, with multiple infundibular aneurysms. There was APVS with free regurgitation and massively dilated pulmonary arteries. The RV bulged into the LV, though there was no outflow tract obstruction. The LV had mildly depressed systolic function. Computed tomography angiography showed marked dilation of the main and branch pulmonary arteries, with compression of the airway. This, along with profound anasarca, prohibited weaning of ventilatory support. Ventricular tachycardia contributed to low cardiac output. Genetic testing revealed a heterozygous variant in the desmoplakin (DSP) gene, which is associated with familial arrhythmogenic RV dysplasia and dilated cardiomyopathy. The parents opted to withdraw care. Severe RV dysplasia associated with APVS and TA has previously been reported, however the degree of RV dilation with primitive myocardium in this case is profound. Further, presence of both fetal and postnatal ventricular tachycardia contributing to low cardiac is a novel presentation. This demonstrates that the overall poor prognosis was multifactorial.     

Long‐Term Follow‐Up of Patients with Syncope Evaluated by Head‐Up Tilt Test

Background: Clinicians may be tempted to consider a positive head‐up tilt test (HUTT) an unfavorable prognostic indicator. We investigated whether results of routine HUTT predict long‐term recurrence of syncope. Methods: We analyzed syncope recurrence at long‐term among 107 patients (mean age 51 ± 20 years) receiving HUTT for diagnostic evaluation of unexplained/suspected neurocardiogenic syncope in our Institute. Results: HUTT was positive in 76 patients (vasodepressive response, n = 58; cardioinhibitory, n = 5; mixed, n = 13). During a median follow‐up of 113 months (range, 7–161), 34 (32%) patients experienced recurrence (24 [32%] with positive HUTT during 110 months (7–159); 10 [32%] with negative HUTT during 120 [22–161] months). Actuarial freedom from recurrence at 10 years did not significantly differ for patients with positive/negative test results (after passive/active phases) or with different positive response patterns (vasodepressive, cardioinhibitory, mixed). By contrast, history of >4 syncopes in the 12 months preceding HUTT stratified risk of recurrence, irrespective of HUTT positivity/negativity. At Cox proportional hazards analysis, history of >4 syncopes in the 12 months preceding HUTT was the single independent risk factor for recurrence both in the overall study population (HR, 1.7; 95% CI, 1.07–2.69) and within the subset of patients who tested positive (HR, 1.83; 95% CI, 1.07–3.17). Conclusions: This long‐term follow‐up study reinforces the concept that a positive HUTT should not be considered an unfavorable prognostic indicator; frequency of recent occurrences may be a more valid predictor. Ann Noninvasive Electrocardiol 2010;15(2):101–106     

Long‐Term Mechanical Consequences of Permanent Right Ventricular Pacing: Effect of Pacing Site

Optimal Right Ventricular Pacing Introduction: Long‐term right ventricular apical (RVA) pacing has been associated with adverse effects on left ventricular systolic function; however, the comparative effects of right ventricular outflow tract (RVOT) pacing are unknown. Our aim was therefore to examine the long‐term effects of septal RVOT versus RVA pacing on left ventricular and atrial structure and function. Methods: Fifty‐eight patients who were prospectively randomized to long‐term pacing either from the right ventricular apex or RVOT septum were studied echocardiographically. Left ventricular (LV) and atrial (LA) volumes were measured. LV 2D strain and tissue velocity images were analyzed to measure 18‐segment time‐to‐peak longitudinal systolic strain and 12‐segment time‐to‐peak systolic tissue velocity. Intra‐LV synchrony was assessed by their respective standard deviations. Interventricular mechanical delay was measured as the difference in time‐to‐onset of systolic flow in the RVOT and LV outflow tract. Septal A’ was measured using tissue velocity images. Results: Following 29 ± 10 months pacing, there was a significant difference in LV ejection fraction (P < 0.001), LV end‐systolic volume (P = 0.007), and LA volume (P = 0.02) favoring the RVOT‐paced group over the RVA‐paced patients. RVA‐pacing was associated with greater interventricular mechanical dyssynchrony and intra‐LV dyssynchrony than RVOT‐pacing. Septal A’ was adversely affected by intra‐LV dyssynchrony (P < 0.05). Conclusions: Long‐term RVOT‐pacing was associated with superior indices of LV structure and function compared with RVA‐pacing, and was associated with less adverse LA remodeling. If pacing cannot be avoided, the RVOT septum may be the preferred site for right ventricular pacing. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1120‐1126)     

Transthoracic Echocardiographic Detection of Pulmonary Valve Involvement in Löeffler's Endocarditis

We are describing pulmonary valve involvement with thickening and stenosis detected by two‐dimensional transthoracic echocardiography in an adult presenting with Löeffler's endocarditis. To our knowledge, this has not been described previously. Complete regression of the lesions occurred with corticosteroid therapy. Tricuspid valve thickening and stenosis and thickening and thrombus formation in the right ventricle also present initially disappeared completely with therapy.     

Comparison of the Acute Hemodynamic Effect of Right Ventricular Apex,Outflow Tract,and Dual‐Site Right Ventricular Pacing

Background: We studied the acute effect of pacing at the right ventricular outflow tract (RVOT), right ventricular apex (RVA) and simultaneous RVA and RVOT—dual‐site right ventricular pacing (DuRV) in random order on systolic function using impedance cardiography. Methods: Seventy‐three patients (46 males), aged 52–89 years (mean 71.4 years) subjected to routine dual chamber pacemaker implantation with symptomatic chronic II or atrioventricular block, were included to the study. Results: DuRV pacing resulted in significantly higher cardiac index (CI) in comparison to RVOT and RVA and CI at RVOT was higher than at RVA pacing (2.46 vs 2.35 vs 2.28; P < 0.001). In patients with ejection fraction >50% significantly higher CI was observed during DuRV pacing when compared to RVOT and RVA pacing and there was no difference of CI between RVOT and RVA pacing (2.53 vs 2.41 vs 2.37; P < 0.001). In patients with ejection fraction <50%, DuRV and RVOT pacing resulted in significantly higher CI in comparison to RVA pacing while no difference in CI was observed between RVOT and DuRV pacing (2.28 vs 2.21 vs 2.09; P < 0.001). Conclusion: Dual‐site right ventricular pacing in comparison to RVA pacing improved cardiac systolic function. RVOT appeared to be more advantageous than RVA pacing in patients with impaired, but not in those with preserved left ventricular function. No clear hemodynamic benefit of DuRV in comparison to RVOT pacing in patients with impaired systolic function was observed. Ann Noninvasive Electrocardiol 2010;15(4):353‐359     

Associations of Hemodynamic Load and Ventricular Repolarization in Patients With Newly Diagnosed Essential Hypertension: A Long‐Term Follow‐Up Study

The evolution of QT interval and its dispersion (QTd) were studied in 135 newly diagnosed nondiabetic patients, as well as the relationship between changes of these left ventricular (LV) repolarization parameters with blood pressure (BP) and LV mass changes, which were prospectively studied for a median period of 3.8 years. At baseline and at last follow‐up visit, all patients underwent ambulatory BP monitoring, echocardiographic assessment, and 12‐lead electrocardiography. At the end of follow‐up, responders of antihypertensive treatment based on a reduced 24‐hour systolic BP (n=122) exhibited a reduction in LV mass index (by 7.6 g/m², P<.001) and corrected QT (by 4.3, P=.038), while corrected QTd was unchanged. In nonresponders (n=13), although no difference in LV mass index was observed, corrected QT increased by 12.4 ms (P=.048) and corrected QTd by 8.2 ms (P=.027). Changes in parameters of LV repolarization were related to BP changes but not to changes of myocardial size.     

An Adolescent with Possible Arrhythmogenic Right Ventricular Dysplasia and Long QT Syndrome: Evaluation and Management

We describe a unique presentation of arrhythmogenic right ventricular dysplasia (ARVD) in a 14‐year‐old Caucasian male who was additionally diagnosed with long QT syndrome (LQTS). Genetic testing eventually confirmed the diagnosis of both ARVD and LQTS, which combined, to our knowledge, has not been reported in the literature.     

Long‐Term Outcome in Asymptomatic Patients with Severe Aortic Regurgitation,Normal Left Ventricular Ejection Fraction,and Severe Left Ventricular Dilatation

Background: Although the guidelines consider severe left ventricular (LV) dilatation a class IIaC indication for surgery in asymptomatic patients with severe aortic regurgitation (AR) and normal LV function, the optimal management remains controversial. We aimed to assess the LV enlargement, hypertrophy and function, and the outcomes in these patients by the presence of severe LV dilatation at baseline. Methods: From our 20‐year database, we identified all asymptomatic patients with severe AR and LV ejection fraction (EF) >50% and ≥2 echocardiograms ≥1 year apart. LV end‐diastolic diameter >70 mm or LV end‐systolic diameter >50 mm or LV end‐systolic diameter index >25 mm/m² defined severe LV dilatation. A composite end point included onset of symptoms or LV dysfunction. Results: Eighty‐four patients (52 ± 18 years, 61 men) were enrolled and followed‐up for 7.1 ± 5.1 years. Two groups were defined: 22 patients with and 62 patients without severe LV dilatation at baseline. The progression of LV dilatation and hypertrophy, and the LVEF at last exam were similar in both groups. Twelve of 22 and 34 of 62 patients (P = 0.59) reached the end point. Vasodilators did not modify the progression of LV enlargement/hypertrophy. Ten of 22 and 25 of 62 patients (P = 0.45) underwent surgery and had similar postoperative LV diameters, mass, EF. Conclusions: The progression of LV enlargement/hypertrophy and outcomes in asymptomatic patients with severe AR, normal LV function, and severe LV dilatation or the postoperative LV parameters were not influenced by the severe LV dilatation, suggesting that a close follow‐up could delay surgery in this population. (Echocardiography 2010;27:915‐922)