Ivabradine in the treatment of non-paroxysmal junctional tachycardia with interference atrioventricular dissociation: A case report.

Ivabradine reduces the heart rate by selectively inhibiting the If current of the sinoatrial node, mainly for the treatment of chronic heart failure with decreased left ventricular systolic function and inappropriate sinus tachycardia, but the inhibitory effect on the atrioventricular node is rarely reported. The patient was admitted to hospital mainly because of intermittent chest pain for 7 years, which worsened for 10 days. Admission electrocardiogram (ECG) considered sinus tachycardia, with QS wave and T wave inversion in II, III, aVF, V3 R-V5 R, V4 -V9 leads, and non-paroxysmal junctional tachycardia (NPJT) with interference atrioventricular dissociation. After treatment with ivabradine the ECG returned to normal conduction sequence. NPJT with interference atrioventricular dissociation is a fairly rare electrocardiographic phenomenon. This case reports for the first time that ivabradine is used in the treatment of NPJT with interference atrioventricular dissociation. It is speculated that ivabradine has a potential inhibitory effect on the atrioventricular node.

A simple preprocedural score for risk of contrast-induced acute kidney injury after percutaneous coronary intervention.

OBJECTIVE: To develop a simple scoring system based on preprocedural clinical features that is capable of predicting contrast-induced acute kidney injury (CI-AKI) before percutaneous coronary intervention (PCI). BACKGROUND: CI-AKI is associated with increased in-hospital morbidity and mortality, prolonged hospitalization, and long-term renal impairment. Although several scoring methods have been developed to determine risk of CI-AKI, no simple scoring method based on PCI preprocedural clinical features yet exists for Chinese patients. METHODS: A total of 2,500 Chinese patients were randomly and retrospectively assigned in a 3:2 manner to create a training and validation dataset, respectively. CI-AKI was defined as an increase of ≥25% or ≥0.5 mg/dL serum creatinine within 5 days after PCI. Preprocedural clinical variables showing independent correlation to CI-AKI were used to derive the risk score from the training dataset and then subsequently tested in the validation dataset. The odds ratios from multivariate logistic regression were used to assign a weighted integer to age ≥70 years = 4, history of myocardial infarction = 5, diabetes mellitus = 4, hypotension = 6, left ventricular ejection fraction ≤45% = 4, anemia = 3, creatinine clearance rate <60 mL/min = 7, decreased high-density lipoprotein <1 mmol/L= 3, and urgent PCI = 3. Summation of the integers represented the total risk score. RESULTS: The overall incidence of CI-AKI in the training dataset was 16.4% [246/1500; 5.4% for low (≤7) and 61.3% for very high (≥17) risk scores]. The rates of CI-AKI, 1-year dialysis, and 1-year mortality increased significantly with each group (Cochran-Armitage test of trend, P < 0.001). The risk score facilitated appropriate classification of patients with low and high risk for CI-AKI after PCI in the validation dataset (c-statistic = 0.82). CONCLUSION: Risk classification based on the most significantly correlated parameters is useful for predicting CI-AKI before contrast exposure. The simple preprocedural score showed excellent predictive ability for identifying patients at high risk of nephropathy and those with deteriorative prognosis after PCI.

[Risk factors and scoring system in the prediction of contrast induced nephropathy in patients undergoing percutaneous coronary intervention].

OBJECTIVE: To develop a simplified risk scoring system of contrast induced nephropathy (CIN) after percutaneous coronary intervention (PCI). METHODS: A retrospective study was performed on 1500 patients in the development set undergoing PCI from January 2008 to December 2009. And 1000 patients treated from January 2010 to May 2011 were selected for the validation set. Logistic regression analysis was applied to identify the risk factors of CIN. Based on the odds ratio, the sum of integers was a total risk score for each patient. RESULTS: (1) Among them, CIN occurred in 246 patients with an overall incidence of 16.4%. (2) Eleven identified variables were identified as the risk factors of CIN (with weighted integer): diabetes (3 scores), hypotension (3 scores), left ventricular ejection fraction (LVEF ≤ 45%) (3 scores), eGFR < 60 [ml×min(-1)·(1.73 m(2))(-1)] (3 scores), age >70 years (2 scores), myocardial infarction (2 scores), emergency PCI (2 scores), anemia (2 scores), decreased high-density lipoprotein (HDL) concentration (< 1 mmol/L) (2 scores), contrast agent dose > 200 ml (2 scores) and low permeability contrast agent (1 score). (3) The sum of integers was a total risk score for each patient. The incidence of CIN was 5.2% in the low-risk group (≤ 4), 13.6% in the moderate-risk group (5 - 10), 32.3% in the high-risk group (11 - 14) and 59.0% in the very-high-risk group (≥ 15). (4) Good discriminative power was found in the validation population. And the risk score was strongly correlated with CIN (c-statistic = 0.82). CONCLUSION: This scoring system provides a good estimate of the risk of CIN after PCI. It may be used for the prevention and treatment of CIN.

Coexistence of 2 types of atrial tachycardias and right ventricular outflow tract tachycardia.

Double tachycardia is a relatively uncommon type of tachycardia. In this report, we discuss a 68-year-old woman with history of frequent palpitations. Electrophysiologic study revealed that narrow QRS tachycardias from 2 origins and 1 wide QRS tachycardia were induced and each of the tachycardias was induced by the other. We found that 2 focal atrial tachycardias and 1 ventricular tachycardia originated from right ventricular outflow tract. All of these tachycardias were successfully ablated during one session, and no recurrence appeared during 10 months of follow-up.

[Upgrading to resynchronization therapy in patients with heart failure after chronic right ventricular apical pacing].

OBJECTIVE: To investigate the clinical efficacy of cardiac resynchronization therapy (CRT) through biventricular pacing in chronically right ventricular apical paced patients with heart failure. METHODS: Ten chronically right ventricular apical paced patients with left ventricular ejection fraction (EF) ≤ 35% underwent CRT upgrading. And the follow-up period was over 12 months. Seven of them reported a significant improvement in their symptoms. Two patients died and one patient had no response. As compared with pre-CRT, CRT significantly improved NYHA classification, decreased left atrium diameter [(43 ± 5) mm vs (46 ± 7) mm], pulmonary arterial pressure [(42 ± 6) mm Hg vs (54 ± 13) mm Hg] and BNP [(184 ± 73) ng/L vs (545 ± 286) ng/L] (P < 0.05), improved left ventricular EF [(35 ± 5)% vs (32 ± 4)%]. Tissue Doppler imaging revealed the maximal difference of time to peak myocardial systolic contraction of 12 left ventricular segment shortened [(136 ± 28) ms vs (97 ± 18) ms], interventricular mechanical delay shortened [(52 ± 5) ms vs (31 ± 6) ms)] after upgrading. CONCLUSION: CRT upgrading from right ventricular apical pacing may improve left ventricular function in patients with heart failure.

Preventive Effects of Nicorandil Against Contrast-Induced Nephropathy in Patients With Moderate Renal Insufficiency Undergoing Percutaneous Coronary Intervention.

We investigated the preventive effect of nicorandil on contrast-induced nephropathy (CIN) in patients with moderate renal insufficiency undergoing percutaneous coronary intervention (PCI). A total of 250 patients with a creatinine clearance (crCl) ≤60 mL/min undergoing PCI were randomly assigned to either a nicorandil group (nicorandil 10 mg 3 times/d and hydration; n = 125) or a control group (hydration only; n = 125). The first end point was the incidence of CIN defined as an increase in serum creatinine (Scr) levels by ≥0.5 mg/dL or ≥25% within 72 hours after exposure to the contrast medium. The secondary end points were (1) changes in Scr, blood urea nitrogen, and crCl and (2) the incidence of major adverse events during hospitalization. The incidence of CIN was 1.6% (2/125) in the nicorandil group and 9.6% (12/125) in the control group (P = .011). There was no obvious difference in the incidence of major adverse events during hospitalization between the nicorandil and the control group (4.0% vs 4.8%, P = 1.000). Multivariate logistic regression analysis showed that nicorandil was a protective factor for CIN (odds ratios = 0.126, 95% confidence interval: -19.996 to -0.932, P = .012). Prophylactic administration of nicorandil may prevent against CIN in patients with moderate renal insufficiency undergoing PCI.

Preventive Effects of Alprostadil Against Contrast-Induced Nephropathy Inpatients With Renal Insufficiency Undergoing Percutaneous Coronary Intervention.

We investigated the preventive effect of alprostadil on contrast-induced nephropathy (CIN) in patients with renal insufficiency undergoing percutaneous coronary intervention (PCI). A total of 300 patients with creatinine clearance (crCl) ≤60 mL/min undergoing PCI were randomly assigned to alprostadil or a control group. The primary end point was the incidence of CIN defined as an increase in serum creatinine (Scr) levels by ≥0.5 mg/dL or≥ 25% after administration of the contrast media within 72 hours. The secondary end points were (1) changes in Scr and crCl within 72 hours and (2) the incidence of major adverse events during hospitalization. The incidence of CIN was 2.7% (4/150) in the alprostadil group, and 8.7% (13/150) in the control group (χ2 = 5.05, P = .043).There was no difference regarding the incidence of major adverse events during hospitalization between the alprostadil group and control groups (2.7% vs 4.0%, P = .750). Multivariate logistic regression analysis showed that alprostadil was an independent protective factor for CIN (odds ratio = 0.136, 95% confidence interval: 0.020-0.944, P = .044). Prophylactic administration of alprostadil may prevent CIN in patients with renal insufficiency undergoing PCI.

Neuroendocrine and haemodynamic changes in single-lead atrial pacing and dual-chamber pacing modes.

OBJECTIVES: Neuroendocrine and haemodynamic changes were compared between single-lead atrial (AAI) or dual-chamber (DDD) pacing modes in patients with sick sinus syndrome, in a crossover study. METHODS: Inpatients scheduled for their first pacemaker implantation were screened for the following inclusion criteria: sick sinus syndrome; intact atrioventricular conduction; normal QRS interval. All study patients were implanted with a dual-chamber pacemaker, programmed for AAI or DDD pacing mode. Patients were allocated randomly to AAI followed by DDD pacing or to DDD followed by AAI pacing, each mode being applied for 72 h. Echocardiographic, electrocardiographic and neuroendocrine parameters were tested at the end of each pacing mode. RESULTS: From 152 inpatients screened for inclusion, 28 were selected for treatment. Plasma levels of atrial natriuretic peptide (ANP), endothelin, aldosterone and angiotension II were significantly lower, and aortic flow velocity-time integral was significantly higher, in AAI mode than in DDD mode. Aortic pre-ejection interval, interventricular mechanical delay and QRS duration were significantly higher in DDD than in AAI mode. CONCLUSIONS: In patients with sick sinus syndrome, DDD pacing mode can induce neuroendocrine system activation, and left ventricular dysfunction and dyssynchrony. These findings discourage the routine use of DDD pacing in patients with sick sinus syndrome.